Track Sharing & Route Sharing.

At about the same time as the first dual-voltage LRV's were being delivered the mainline railway developed a shortage of rolling stock for local trains, so to 'help out' some LRV's were lent to the mainline railway to provide local services between Karlsruhe and the nearby town of Pforzheim. This line was (and still is) also used by international express passenger & heavy freight trains and all services continued as if nothing special was happening. However, much to the various transport authorities surprise an increase in patronage was noticed that could only be attributed to the nicer environment of the more modern LRV's.

February 1992, and due to a shortage of 'heavy' trains some light rail vehicles replaced main-line local services between Karlsruhe and the nearby town of Pforzheim. International, InterCity, and freight trains continue to use this line - which is fitted with Automatic Train Protection signalling.

Click either the projector icon or here to watch a short film on 'youtube' showing local trains, heavy freight trains, international InterCity express trains and even steam trains as well as the light rail calling at this station (or passing through without stopping).
The video was sourced from two trips in the summer of 1992 and 1994.

Since the pictures above were taken Karlsruhe has greatly expanded its track sharing.

At first overcrowding became a problem which initially was solved by running 3-unit trains, although as soon as possible the timetable was recast with increased services to meet the high demand. Then they drew up plans to extend the system to other routes too.

Nowadays the 10 route network of the 'Karlsruhe Stadtbahn' (regional lines) requires more than 120 'Stadtbahn' tramcars, extends to over 400km almost 250 miles in length - and is still expanding.

Included in the network are some 'inter-urban' and 'InterCity' services to nearby towns such as Heilbronn in the neighbouring Neckar region and Baden Baden, which is on the mainline towards Switzerland. Many services track share with all manner of (international) freight and passenger trains - including sometimes the very high speed ICE (InterCity Express). Typically the LRV's provide the 'all-stations' local services whilst 'heavy rail' trains provide the long distance non-stop express services, although on some routes the LRV's also operate semi-fast and 'Sprinter' (mostly non-stop) services. In some towns the services have been extended beyond the mainline railway, in the process requiring the construction of new sections of urban tramway so that 'seamless journeys' can be provided between town centres and the pre-existing mainline routes.

One issue yet to be resolved is that the tracks through Karlsruhe city centre are now too congested for all the additional services so it is planned to build a tunnel under the pedestrian zone. In the meantime some services still terminate at the main railway station.

The dual-voltage Karlsruhe light rail vehicles are often called Tram-Trains. This has become a generic term for what effectively are trams that venture on to the mainline railway. Conversely trains which venture onto urban tramlines within the street environment have become known as Train-Trams.

In addition to Karlsruhe...

Spurred on by Karlsruhe's success many other cities have investigated track sharing too. It is not intended to list every proposed such scheme, however coverage of the locations featured below should provide sufficient information to understand what the concept is about and some of the possible options for its wider implementation - especially here in Britain.

It should also be noted that whilst the original ethos in Karlsruhe was primarily to provide better and through transport links between rural mainline services and the city's central business district the concept has moved on to include being seen as a cost effective and affordable way to help revitalise under-performing passenger services and to introduce new passenger services over little-used existing freight-only lines.

More 'Heavy' / 'Light' Rail Track sharing solutions...

In 1995 and 2001 Kassel, Germany extended its urban tramway services over two outer-suburban little-used freight lines in the south-east and the south-west of the city. Both services have proven to be very successful; for instance passenger loadings on route No. 5 soared from 2800 to 5800 daily - an increase of 110%. At most these lines carry just a handful of freight trains, which run during the day. The lines are fully signalled, as per normal mainline railway lines.

Encouraged by this success Kassel has introduced twin fleets of tram-trains for a range of services which were gradually introduced during the period of 2005 - 2007. 18 of these 36.7m long, 2.65m wide, 100km/h light rail vehicles are of the dual voltage variety (15,000v ac and 600v dc) and 10 are twin system diesel electric, with diesel mode being used on non-electrified mainline railway routes. The aim has been the creation of a Karlsruhe-style regional light rail system with through services combining mainline railway and street tramway operation. These operate under the banner of "RegioTram".

Track sharing has also proven successful in eastern Germany too.

So far three locations are involved - each of which has seen the successful application of a different solution.

In Chemnitz a new link was built from the tramway to the mainline railway to Stollberg, which was also electrified. Passenger services re-started in December 2002 and have been a tremendous success. When mainline services ceased this route saw just 900 passengers a day, yet within a few years of reopening it was carrying over 6500 on weekdays, 3000 on Saturdays and 1500 on Sundays. The line still carries some mainline freight and diesel multiple-unit passenger trains.

In 2004 a fleet of innovative trams fitted with an auxiliary fossil fuel (diesel) traction package commenced operation in the town of Nordhausen. These operate as regular electric trams on the city streets and as fossil fuel powered trams when travelling over the (not electrified) privately owned HSB's (Harz Narrow-Gauge Railway - Harzer Schmalspurbahn) to Ilfeld, where they supplement services already provided by the railway's own diesel trains. .Incidentally, this line also operates some tourist - orientated steam trains, and the relevance is that the combination of tourist and local community operations shows how tourist services can generate income which both benefits the local economy and helps to sustain otherwise potentially uneconomic local services. Britain has many rural rail lines which serve areas which are (or could) be attractive to tourists too.

In Zwickau some regional services provided by modern diesel multiple-unit trains have been extended to share part of the urban tramway, travelling through city streets to the heart of the town centre. To conform to the regulations for use on the public highway the diesel trains (which are of a type known as regiosprinter) have been equipped with lights and mirrors. Because the urban tramway uses 1 metre (1000 mm) track gauge and the diesel trains use standard gauge (1435 mm) an extra (third) rail was installed, with the trams and trains each using one common rail and one exclusive rail. Zwickau is part of the Vogtland region, this being served by the Vogtlandbahn regional railway which provides train services in an area comprising not only the Bundesland Saxonie but also parts of Thuringia, Bavaria and even the Czech Republic.

Despite introducing more diesel powered vehicles to urban streets Zwickau's 'train-trams' have proven to be a successful solution to bringing local railway services closer to the town's central core. Anyway, since most British transport advocates and "green" lobby groups see wider use of diesel motor buses within even the largest of British towns and cities as "highly desirable" (even though diesel exhaust fumes are a known hazard to human health) then maybe there could be a case for steel-wheel based urban transport solutions here in Britain to use a similar traction package???

International travel - from Germany to France.

Another German city which has combined regional and urban transport making use of modern multi-system light rail vehicles is Saarbrücken. As in the Karlsruhe area this system has also seen the replacement of local mainline trains with tram-trains, with services also extended to travel through city streets. However as Saarbrücken no longer had an urban tramway system the street tracks had to be installed from new (similar also occurred as the Karlsruhe system expanded and tram-trains started to serve nearby towns which did not have street tramway installations). Where Saarbrücken's system is unique is that it is an international service which extends over the border into France.

Having seen the success of this system the French have been looking at more locations where the use of tram-trains could be beneficial. The ethos behind this includes introducing / restoring passenger services to goods-only lines and seeing if the conversion of lightly loaded heavy rail passenger services to light rail, perhaps with services extended beyond the mainline railway tracks and into the centre of nearby towns can provide a cheaper, more cost effective and passenger-enticing way to operate the services - and even 'save' a rail line which otherwise would be threatened with closure.

Several of the new French tramway / light rail lines which opened in 2006 involve track sharing, with (limited) freight services remaining possibilities...

• Line T4 in Paris where the mainline railway (RFF) still owns the tracks & the light rail vehicles are known as tram-trains;
• Line 2 in Montpellier which for several km in the Saint-Jean-de-Vedas both shares its right of way with RFF as well as including some actual sharing of tracks - where there are even notices by RFF welcoming the tram line to the RFF network.

Also in France, December 2010 saw an example of Karlsruhe-style track sharing commence operations on a 22km interurban route between Mulhouse and Thann-Saint-Jacques. The tram-trains travel at up to 70km/h (45mph) on the tramway, which is also used by other street trams and is energised at 750v dc, and 100km/h (62mph) on the railway line, which is electrified at 25kV 50Hz.

Track Sharing In The Netherlands

The Dutch are also implementing a Karslruhe - style track sharing solution. This is on the RijnGouweLijn (RGL) light rail project in South Holland.

The shared track is from Gouda through Alphen aan den Rijn to Leiden. The existing heavy rail track is being adapted and seven additional stops added. The line will then extend through Leiden Centraal railway station and then travel over new track to Katwijk, with a branch to Noordwijk.

In the meantime however tram-train services have began using the mainline route between Gouda and Alphen aan den Rijn. For this the stations have been adapted with new low level platforms being added - either as extensions to existing high level platforms or by building them on the opposite side of the track to the high level platforms.

Although generally proving popular there has been some adverse comment because unlike the mainline trains the tram-trains do not include provision for first class passengers, and do not have toilets. One feature which they offer which was lacking on the mainline trains is the forward view through a window behind the driver's cab.

Track Sharing In Italy.

Slowly evolving on the Italian island of Sardinia, the Sassari Metro-tramway is a light-rail public transport system where the trams run on the tracks of an urban tramway network and also on the existing suburban narrow gauge railways operated by the Ferrovie della Sardegna (Railways of Sardinia). Street tramway operations began in 2006 and in 2009 the trams were extended over the tracks of the heavy railway. This system is still very much in its infancy, with much of the tram-train network still under construction or in the advanced development phase.

Track Sharing In Spain.

Also slowly evolving, the Alicante TRAM (Metropolitano de Alicante/ Metropolità d'Alacant) operates in the Spanish city of Alicante and its surrounding area and, like the other narrow gauge railways of the Valencian Community, is run by the Ferrocarrils de la Generalitat Valenciana (FGV). It was inaugurated in 2003 replacing narrow gauge diesel trains.

And here in Britain?

Here in Britain many transport advocates saw the triple digit increases in passenger numbers in Karlsruhe and began to wonder if similar could become part of the wider British transport scene. As might be expected the reasons were (are) similar to those in Europe, as well as trying to find ways to improve passenger loadings on under-used rail lines - especially those with infrequent services and / or where the stations are not conveniently located (with the light rail using short street-based deviations to better located stations) and restoring local passenger services on routes currently only used by freight trains.

In 1994 the Cardiff Bay Development Corporation proposed a tram-train system featuring track sharing with local mainline trains on the Cardiff Valley lines, with services then extended through urban streets to reach central and southern areas of the city. However the HMRI (Her Majesty's Railway Inspectorate) who at the time were the body concerned with railway safety proved to be unwilling to give their approval and the scheme died.

Whilst both the Manchester Metrolink and Croydon Tramlink systems have been very successful in revitalising formerly closed and open but under-used mainline railway routes it should be noted that they were both complete conversions from heavy rail to urban tramway / do not involve any aspect of track sharing.

Transport "experts" seemed surprised that when the trams took over the former mainline service between Wimbledon and West Croydon there was a very significant 700% increase in passenger loadings.

Perhaps it was because the tram service took people where they wanted to go (ie: into the heart of Croydon) without additional travelling? Or maybe that a mainline train at the somewhat bizarre frequency of every 44 minutes was just plain 'passenger repelling' whilst a tram every 10 minutes (or even more frequent) is 'passenger enticing'?

Now there is a shortage of trams and at busy times overcrowding has become a problem.

Track sharing was proposed for part of the Nottingham NET tramway but instead it was decided to use route-sharing, which is not quite the same (see below). In Manchester most of the original sections of Metrolink saw existing heavy rail trains completely replaced with the light rail vehicles, with (on the Altrincham route) some longer distance mainline passenger services being quite literally 'thrown off' their existing route and forced to take a longer, slower detour. With track sharing this would not have been necessary - although admittedly it is possible that sometimes the non-stop heavy rail services would have been delayed behind the all-stations trams. But that is a different issue...

The first British location where light rail and heavy rail vehicles share tracks is on part of the Sunderland extension of the Tyne & Wear Metro - but here the situation is different because although the Metrocars follow some light rail philosophies they were designed at the 'top' end of the light rail gamut being as much 'heavy' light rail vehicles as 'light' heavy rail vehicles. Furthermore, the service they provide is more akin to what is known as a light metro than light rail. Unlike the tramcars used in Blackpool, Manchester, Sheffield, West Midlands, Croydon, Nottingham and on the Wirral, the Tyne & Wear Metrocars are not street compatible - which means that (unless modified) they are not suitable for use in the street environment - either using street tracks shared with other traffic or unfenced right of ways alongside the roads / footpaths.

As yet it seems that the Tyne & Wear Metro's Sunderland extension has not been an immediate rip-roaring success of the type seen in locations such as Karlsruhe and Croydon. To be fair however, it could be that even comparing with these other locations and their triple digit percentage increases in passenger numbers is an act of folly. It needs to be bourne in mind that simply introducing a new service is not always in itself enough to ensure that passengers flock to them. Whilst people do like travelling by rail transports (of all kinds) they still have to offer benefits which are tangible. Otherwise they become mere joyrides for tourists and transport enthusiasts - which is not what urban transport is about. The question of 'success' is complicated by government policy which seems to be only really interested in financial results - which need to become apparent 'asap' (and not other longer term socio-economic benefits). This latter point is relevant because the lack of apparent and instant success for the service to Sunderland (as well as the Manchester Metrolink Eccles extension and the Midland Metro) seems to have served to poison the water with respect to obtaining government investment funds for tram / light rail schemes elsewhere - especially Leeds and Liverpool / Merseyside - where large sums of money were spent preparing for the trams, only to have matters financial cause the proposed systems fall over at the last hurdle. It did not help however that the governments' onerous financial criteria made the proposed systems cost more to install than they otherwise would have. Indeed the situation is such that the financial equation even has to include the treasury's loss of tax revenues from people not buying motor fuels (petrol / diesel) because they have switched to the new public transport!

Manchester's Eccles line shows what can happen when the transport runs unreasonably s-l-o-w-l-y; Birmingham (Midland Metro) shows what happens when government penny-pinching means that the 'starter line' fails to reach a logical traffic destination (yet despite being incapable of doing so is still expected to wash its face financially) whilst Sheffield shows how people can be 'price sensitive' and that it is crazy to install the transport at the same time as demolishing the residential estates the transport was installed to serve! Experience in Nottingham shows that when the trams serve logical destinations, complement with (instead of compete against) local buses and include park & ride facilities then even in Britain trams can be successful - even when judged by onerous (hostile) government / treasury financial benchmarks!

When looking at converting lines to light rail and introducing track sharing it needs to be bourne in mind that replacing fast services with slower services is not necessarily the excellent, passenger attracting solution which some advocates suggest it could be. Whilst the faster rates of acceleration of the newer light rail vehicles will usually help plug the top speed gap the overall journey times may still be slower. It may be that the people who no longer need to change trains to reach their ultimate destination will benefit from the new service (especially if the time taken to change trains is included in the equation), however people travelling to locations within walking distance of stations served by the mainline trains (in this case Newcastle Central and Heworth) may not, so for them any benefit from a more frequent service (if this is applicable) has to be counter-balanced with the disbenefit of longer overall journey times. This especially applies to the people from whose local stations the faster service has been withdrawn. Of course passengers using any of the brand new intermediate stations will benefit from new services nearer to where they live, but that is a different issue. It is also worth remembering that there may be faster (and competitively priced) road transport alternatives.

It should be noted that the Karlsruhe, Saarbrücken and Kassel tram-trains are all capable of 100km/h (62mph) whilst the Metrocars have a maximum speed of just 80km/h (50 mph). Also, in Germany & France the mainline routes are electrified at mainline voltages - not only is the 1500v dc of the Metro system simply incapable of benefiting freight or other mainline services but it even precludes the introduction of same. Maybe however when the Metro's rolling stock is renewed so the replacements will be of a dual voltage design, so that mainline railway can be re-electrified at the standard mainline voltage, which here in Britain is 25,000 v ac.

The section of line beyond Sunderland to South Hylton is mostly a closed line which has been reopened. As such it could be that expectations of instant passenger number surges are unrealistic? Maybe - as with the reopening of closed lines which form part of London's Docklands Light Railway - the South Hylton line's primary initial expectations should be to act as a catalyst to spearhead local inward investment, creating the employment and housing which will eventually bring in the passengers? As a local person suggested, at present this line does have minimal traffic potential... this line is a route from the edge of an industrial estate to the middle of nowhere.

As an aside, in the specific case of transport in the Tyne & Wear region, it could be that it would have been better (in the long term) if in the 1960's the 3rd rail electric railway had not been de-electrified. The city centre tunnels which were built for the Metro could still have been built, albeit as part of an existing electric mainline suburban railway system - as in Liverpool / Merseyside. Many of the other benefits of the Metro could still have been achieved, including new stations, bus integration, airport extension, new style trains, etc., - indeed as with the Metrocars the LNER's electric trains of 1937 were also of an articulated design. The extension of electric services to Sunderland would still have been possible, in the same way that the Merseyrail system (as it is now known) has been extended to Chester and other destinations. The retaining of mainline trains would also have had other benefits too. Until the creation of the Metro the routes involved were open to all trains, whether passenger or freight. The total handover of the Tyneside loop from British Railways to the Metro (without track sharing) resulted in services such as the summer specials which travelled from locations 'far and wide' elsewhere in Britain (heading for destinations such as Whitley Bay) no longer being able to make these journeys. Excluding these services actually harmed the wider railway network. With track sharing there is no need to split off individual lines for dedicated services in this way.

The first British 'Train-Trams'.

In March 2008 it was announced that there would be a trial of train-trams on the rural British railway route known as the Penistone Line which links Huddersfield with Sheffield. Two of the reasons why this line was chosen are that it creates a possibility for phase 2 of the trials to include extending the train-trams into Sheffield city centre by sharing the tracks of the Sheffield Supertram system and that this line has a Community Rail Partnership designation, with there being a well-informed highly active local rail user group.

The justification for the experiment was stated to be that tram-trains...

are lighter and 'greener' than conventional trains. They use less fuel and weigh less, which reduces wear and tear on tracks therefore decreasing the need for disruptive maintenance works. They have faster acceleration and deceleration rates so they can also offer passengers better journey times.

Among the (technical) issues to be faced are:-

• How to ensure safety with regard to the gap between platform edge between light rail vehicles which are 2.65m in width at mainline stations designed for trains which are 2.8m wide
• How to ensure accessibility for light rail vehicles which (most likely) will be designed for 'low' level tram style platforms but also need to call at stations with the traditional British 'high' platform.
• How to ensure wheel compatibility of light rail vehicles so that they can operate on both mainline and tramway style tracks, which although similar in theme are very different in detailed technical standards.

In some ways it does seem that what is being proposed here is primarily about finding ways to make existing railways cheaper to operate (which in itself is a worthy cause) with any potential benefits from better rolling stock or services being of secondary importance (fortunate spin-offs). That said, it was a fortunate and unexpected spin-off when passenger numbers increased after the shortage of heavy rail trains resulted in a temporary use of light rail vehicles on the German route between Karlsruhe and the nearby town of Pforzheim.

At present many services on this route are provided by class 144 'Pacer' trains, which are of a design built by the former state owned British Railways with the primary aim of being as cheap as possible, with their intended use being on socially necessary routes which were not deemed to be financially viable. As such they already fulfil some of the requirements for 'lighterweight' mainline trains - indeed it is not for nothing that some transport pundits have (rather unkindly) asked whether these Pacer trains are 'light' heavy rail or 'heavy' light rail. Similar trains serve (or have served) many areas in Britain with many of the passengers who use them frequently being less than wholesome in their praise of their antiquated basic design (eg: the single wheel / no bogie design dates from the very early days of the railways and results in a lower quality of ride). Therefore many passengers would be happy to see their replacement with more modern and attractive 'light rail style' rolling stock.

In Europe several such designs of lighterweight trains already exist. The train-trams of Zwickau are just one example. Here in Britain there are many routes where such trains would be an improvement over what is currently used.

It could therefore be asked whether what is being proposed for the Penistone Line will prove to be little more than an evolutionary process downwards from heavy rail? To a large extent this will depend on the type of rolling stock which is used. Perhaps rolling stock of the type seen below would be more appropriate for this route?

In September 2009 it was announced that the tram-train trial would be switched to a different route. The new proposals are for the service to start at Sheffield city centre and travel over the existing Supertram tracks as far as the Meadowhall Interchange where they will switch to mainline railway tracks and continue on to the nearby town of Rotherham. The stated reason for this change of plan is that electric tram-trains were found to be more economically viable.

It is assumed that the new service will be instead of government supported plans to introduce (even more) competition for the Sheffield tramway in the form of a rival bus rapid transit service linking Sheffield with Rotherham.

The section of mainline railway route to be served in these trials will need electrifying before services could commence. As yet it remains to be seen whether this will be at the mainline railway voltage of 25,000v ac or tramway voltage of 750v dc. The significance of this is that if at railway voltage then the route could be used by other electric trains too - something which is not possible on the section of shared track used by Tyne & Wear Metrotrains heading towards Sunderland.

In October 2009 a second tram-train trial was announced. This will see tram-trains replacing mainline passenger trains on the branch line between Watford Junction and St Albans. Watford is just outside London (to the north) and the line is electrified at 25,000v ac using overhead wires. It is assumed that the freight trains which use this line will continue to be able to do so. The official press release announcing these proposals included the following:

The proposed improvements would enable passengers to travel between St Albans and Watford on a regular half-hourly tram and allow for the possibility of an even greater frequency of three trams per hour. The trams would replace the existing train service link, which currently operates on an irregular schedule with just one train every 45 minutes, providing a better service for around 450,000 passengers a year who currently use it.

The images below show some possibilities for the British tram-train trials. Both examples come from France.

Track Sharing between different
types of 'Light' Rail and Light Rail & Métro.

In Holland they wanted to improve transport between the town of Amstelveen and its neighbouring city of Amsterdam.

The solution they found was to extend Amsterdam's tram line No.5, and create light rail line No.51 which would be operated with a fleet of special twin system LRV's that in Amsterdam would share part of the (3rd rail) métro (both underground & at surface level) and in Amstelveen share a reserved section of track with the (overhead wire) street tram route No.5.

Although the shared 5 + 51 route is within the 'street environment' different wheel profiles (and the lack of 'high level' platforms at stops) makes the dedicated fleet of twin system LRV's incapable of running along street trackage shared with road vehicles. They may be light rail vehicles but they are not trams!

To maintain 'easy access' for the trams on route 5 (which are designed to call at kerb height platforms) and the LRV's on route 51 (which use high floor platforms) the stations on the joint route feature extra long dual height platforms with the different types of vehicle calling at separate portions.

When operating on the shared métro tracks the LRV's on route 51 are supposed to follow close behind the much larger (as in "longer and therefore higher capacity") métro trains. This is to prevent overcrowding.

Because of the width difference between the LRV's and métro trains it was felt desirable to find a way of plugging the gap between the vehicle and station platform edge. This has been achieved by means of a step plate which is raised when travelling over sections of track where the stations were constructed to be suitable for metro rolling stock.

Track sharing between different types of heavy rail is not new, after all passenger and freight trains have shared the same tracks for many years. But, there is a significance in London with its underground railway which comprises of two different 'types' of train, a small profile (often called 'tube' train - because part of their route network involves running through small circular 'tubes' deep underground) and a larger profile which uses trains of similar dimension to mainline trains.

In addition to underground trains of these different profiles sharing tracks there are several places where the underground and mainline services share trackage. These services date back to before the formation of London Transport in 1933 and are more accidental historical survivors rather than sensibly planned joint services.

The Metropolitan Line was originally planned as a mainline railway and in addition to its own steam trains also carried other companies' InterCity expresses between London (Marylebone) and Manchester via Aylesbury, Rugby, Leicester, Nottingham and Sheffield. British Railways killed off the longer distance trains in the 1960's, but outer-suburban Chiltern Railways services to Aylesbury via Amersham still use London Transport's tracks for part of their journey. For many years the Metropolitan also served Aylesbury, but the line beyond Amersham was given to BR when the last Metropolitan locomotive-hauled trains were withdrawn from service.

Although very rare InterCity 125 trains have been known to have used this line.

The other location where mainline trains use trackage owned by the Underground is on the Wimbledon branch of the District Line. Until railway privatisation in the mid 1990's these tracks were actually owned by British Railways although since 1939 only the Underground provided a regular (local) passenger service over them.

Track Sharing between computer and human driven trains.

For a number of years London's underground railway used to host an instance of track sharing between automatically (computer) driven trains and manually (human) driven trains. This was on the Hainault - Woodford section of the Central Line, and its reasoning was as part of the development of the automatic train control system which eventually became used on the fully automated Victoria line which opened in the late 1960's.

On the Central Line test-bed the automatic trains provided a local shuttle service whilst the human driven trains were peak hour extras (and depôt journeys) which added to the base service. Although more recent resignalling of the entire line and introduction of new trains means that this form of track sharing no longer exists, while it lasted it proved that computer and human driven trains can safely co-exist.

Track sharing between different transports - Rail and Bus.

Apart from all-rail track sharing there are / were places where buses run on special tracks shared with trams. Both examples come from Germany, and involve kerb guided buses, this being a bus-on-rails technology which is also known as O-Bahn. There is no reason why similar could not be achieved here too - as ever 'human politics' is the biggest hurdle to overcome. (Guided buses are looked at on this page.)

Route Sharing.

With route sharing the transports will operate alongside each other whilst retaining their own tracks. Compared to track sharing this has both advantages and disadvantages. Route sharing will be the only option for locations where the trains have incompatible physical or operating characteristics.

The advantages include:-

• A delay on one service will be less likely to also affect the other line.
• Where the trains have different operating characteristics (such as some use fully automated 'computer driven' trains whilst others require a human driver at the front) route sharing is easier to manage.
• It is easier to arrange full accessibility for trains of different physical dimensions which require station platforms to be of different heights.
• For busy services with different stopping patterns (ie: not all trains call at all stations) it may be easier to operate 'fast' and 'slow' trains if they are kept apart.

The disadvantages include:-

• Can be inconvenient to passengers if they have to choose at which platform to wait for the next service, and they make a wrong choice!
• Extra tracks, station platforms, etc., require more land space plus cost more to build and maintain.

Examples of Route Sharing.

Route Sharing is used so much here in Britain that it is possible to show six different examples - all of which come from within these shores!

The suburban rail line out of London's Fenchurch Street station demonstrates both route sharing with light rail and different types of types heavy rail.

Route sharing with light rail involves the Docklands Light Railway, which features high frequency computer driven trains. When it was built the DLR "took over" one pair of the mainline railway's tracks (at the London end of the route) with the mainline railway retaining the other pair. At the time there was some criticism of this, but it should not have adversely affected the mainline services because with so many former destinations no longer served the mainline railway was considered to not be making full use of all four tracks and, anyway, much of the remaining route only features one pair of tracks. Furthermore it is worth noting that the DLR needed the pair of tracks because it effectively re-opened some of those formerly closed lines which many years ago used to be served by trains from Fenchurch Street station.

Further out into east London the Fenchurch Street services route-share with the London Underground. In the days of steam locomotives the mainline trains also used both pairs of tracks here too - in the process sharing tracks used by the electric underground trains - but when (in 1962) the mainline was electrified the two sets of trains were totally segregated with services being recast so that the underground had exclusive use of one pair of tracks for the local 'all-stations' service whilst the mainline trains retained the other pair of tracks for longer distance services - cutting out all except one intermediate station (Barking) - which was rebuilt to provide a convenient cross platform interchange facility between the two services. As an aside the opening of the Jubilee Line in 1999 saw the creation of brand new platforms (at West Ham) to facilitate interchange with the new underground line. This is a station which the mainline railway had previously not served.

Incidentally, until the start of WW2 this route also hosted some through trains (which were named the Southend Corridor Express) and ran from Ealing Broadway in west London along the District line through central London to the seaside town of Southend-on-Sea, changing between electric and steam locomotive haulage whilst calling at either Barking or East Ham stations in east London (not illustrated)

Route Sharing examples on the route out of London's Fenchurch Street Station.

A Route Sharing example from elsewhere in east London.

Also in east London the 1999 extension of London Underground's Jubilee Line to Stratford created another instance of route sharing between underground and mainline trains - this being the easternmost section of the North London Line. Although the mainline service here was very infrequent (so infrequent that it actively deterred many would-be passengers) and exactly the same mainline trains (class 313) already track share with London Underground trains in two other locations (District and Bakerloo lines) it was decided to keep the services on their own independent tracks. The reasons for this included:-

• The legal requirement for the underground railway (being a brand-new installation) to be fully 'accessible' which would have seen the need for extra long dual height platforms with different sections for the different size trains.
• The known dislike by the health & safety people for track sharing between London's small profile tube trains and mainline sized trains - of any operator, including the services provided by the London Underground.
• A future desire for the Jubilee Line to use automated (computer) driven train control systems.
• To avoid delays to the mainline service caused by Jubilee Line trains queuing to enter Stratford station (which for them is a terminal station).
• To "future proof" the services because long term plans included replacing this section of the North London Line with Docklands Light Railway services - and the DLR's third rail power system is physically different (incompatible) with that of the underground.

That last point is perhaps the most significant, because in late 2006 the mainline services were withdrawn from here, and at the time of this update (April 2007) the section of railway which route shares with the Underground is poised to be converted to become part of the DLR's branch to Stratford International station (for 2012 Olympics and Eurostar trains to France & Belgium).

For the record there are several more examples from the London area which could be mentioned (featuring mainline trains and either London Underground services or Croydon's trams) but these examples should suffice as demonstrations with respect to what Route Sharing is about.

Apart from London.

Out of London four systems feature instances of route sharing between light and heavy rail:- The Midland Metro. The Nottingham Express Transit, The Manchester Metrolink, and the Tyne & Wear Metro. (The latter is in addition to the track sharing elsewhere on the system)..

The Nottingham and Greater Manchester systems include level crossings on the route shared sections of line and for safety reasons it was decided that in such circumstances there should have be one organisation with ultimate authority over all railway operations at the crossing - this being a duty undertaken by the mainline railway track authority.

Track and Route Sharing Issues & Comparisons - In A British Context.

Whilst the introduction of the light rail services seen above has proven to be beneficial to the local communities served it could be considered to be unfortunate that because track sharing was not used there has been a certain amount of disbenefit to some mainline services too (especially non-local services which originated from elsewhere in Britain).

On the Manchester Metrolink's Altrincham route other mainline services which originated from beyond this line were forcibly evicted, although fortunately it was possible to find an alternative (albeit slightly longer) railway route in to Manchester which was able to accommodate the displaced services.

When it was first opened some locations on the Tyne & Wear Metro included bi-directional sections of single track, so that on twin-track sections of former mainline railway freight services could route share using the other track. However, because (at the time) track sharing was not permitted the total handover of the Tyneside loop from British Railways to the Metro resulted in services such as the summer specials which travelled from locations 'far and wide' elsewhere in Britain (heading for destinations such as Whitley Bay) no longer being able to make these journeys. With track sharing these services could have continued to operate - OK it could be that with the changing travel patterns these trains would have been discontinued anyway, however that is a different issue.

What IS being suggested is that the complete isolation of sections of the railway just to create urban rapid transit systems (using any of the possible transport technologies) is of questionable benefit if it also disbenefits services from elsewhere. As was found during the time of Dr Beeching, 'chopping off' the branch lines can result in harm to the mainline too. (By means of reduced passenger flows because of the breaking up of the previous seamless journeys). This is also a fares & ticketing issue - wherever possible through ticketing should also remain - preferably not just for people travelling from afar to the route being shared, but also for local passengers travelling away from the shared route. This is to avoid financially disadvantaging the passengers...

With track sharing it is possible to maintain the unified railway, even for the occasional longer distance passenger service from outside of the area. Track sharing also means that freight trains can be accommodated too - even if only at night, when light rail passenger services are not running.

A Track and Route Sharing Comparison - With The Roads

It is understood that when prohibiting instances of track sharing the various officials are concerned about safety - so even though some of their decisions may prove to be detrimental to better local passenger rail services their reasons could be said to be for the highest good. After all, with rail-based transports the theme is one of 'safety first', and no matter what else (trains which run late, are overcrowded, expensive, etc) passengers have an expectation of absolute safety.

However, all this makes a stark contrast with the situation on the roads where there are no similar restrictions on mixing very heavy, and demonstrably dangerous, freight trucks / heavy goods vehicles with small, light, vulnerable passenger cars, motor cyclists etc.

The roads are where the real danger lies - and it is very possible that there will be occasions when by by refusing to permit the far safer mixing of light and heavy rail so the various railway / railroad safety officials are de facto adding to the danger on the roads - because people who would have used the public transports / transits, had they been allowed to operate, are instead travelling by road.

Similar double-standards apply to level crossings - for the roads just about any vehicle can cross the tracks, and although there are usually warning lights, bells / sirens and sometimes some sort of lifting barrier or gate which provides for physical obstructions motor vehicles still frequently manage to break the rules, very often causing accidents as a result - which (in the news media and public perception) are almost always blamed on the railway, even though it is usually totally innocent of wrong doing. As a contrast, where tramways / light rail services cross tracks belonging to heavy rail services so the most stringent restrictions are applied with signalling system interlocking to ensure that collisions are avoided.

Track and Route Sharing Issues & Comparisons - The USA.

In the USA all attempts at promoting track and route sharing are being pro-actively resisted by the Federal Railroad Administration (FRA) and the various private US railroads. Partly this is because their lawyers are very 'risk aware', which means that they just do not want to allow anything that might even remotely involve a risk - even where none exists.

However the FRA looks more favourably upon the idea of temporal separation ("time-sharing") of trackage which means that the different types of train (tramway / streetcar and other light railway or heavy rail intercity freight) have exclusive use of the tracks within clearly defined time period. This is how the San Diego Trolley is able to use a freight railway line between central San Diego and San Ysidro (Tijuana) - the trolleys (trams) run until late night, then freights take over and run in the middle of the night. The different types of train are not on the same lines at the same time. But temporal separation only works for fairly lightly used freight lines, and it rules out any kind of 24-hour LRT service on the line.

The following information comes from a US based transit advocate. It more deeply explains some of the issues.

Mike is absolutely correct. Just so European rail advocates and professionals are fully aware, this is a very serious issue here in the USA, and it is becoming more so. The FRA imposes severe restrictions on common shared usage of trackage that virtually prohibits "tram-train" service on the European model.

Lately the FRA has been expanding this rule to restrict even joint shared usage of right-of-way, even if it is on separate tracks. In Raleigh (North Carolina), this has meant dumping of a tramway (LRT) scheme in favor of a "heavy" DMU railway alternative; then the parallel railway imposed severe spatial separation stipulations (although the rail transit service was proposed on separate tracks). The costs eventually were driven so high that the benefit-cost ratio was jeopardized, so that the Bush-controlled Federal Transit Administration saw an opportunity to demand a recalculation of ridership under much more arduous rules - and voila! The proposed service failed to meet the FTA criteria. Sound like the "poor value for money" line of the UK's DfT? Hmmm...

Most recently, this policy has been further expanded, and adopted by major privately owned railroads. For example, in Denver, the BNSF is refusing to accept an LRT (tramway) alignment in its right-of-way, forcing the Regional Transit District to propose a "heavy" DMU scheme which it is now finding difficult to justify.

Meanwhile, transit advocates here continue to use Europe's example of safe, efficient operation of the "tram-train" strategy to pound away at the absurdities of US transport policy.

In Portland, the MAX LRT runs alongside the Union Pacific's track for a stretch along the Banfield Expressway alignment. The LRT tracks are shoe-horned in between the freeway lanes and the railroad - there's a rather good photo on NYCSubway.org: http://world.nycsubway.org/perl/show?18524 I'm not sure about the degree of separation (i.e., how many feet/meters) between the LRT and the railway ... but FRA (and private railroad) rules here are becoming more and more onerous, so that I would doubt transit planners will have such routing opportunities available today in most cases.