Light Rail Fits In

Road Junctions, Level Crossings
And Traffic Signal Priority.

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This page primarily looks at some of the different types of signalling systems for where light rail and road traffic, pedestrians etc., interact.



`Stuttgart, Germany - to comply with German law and reduce the possibility of road traffic becoming confused and mistakenly following signals which are dedicated to the light rail, the system uses distinctive 'white' signals when operating within a street environment and more traditional railway style 'colour light' signals elsewhere.`

When Operating In The Street Environment.

Whilst in the street environment light rail will typically operate in street tramway mode - which means being driven 'on sight' - just like all the other road traffic. However it usually benefits from facilities such as dedicated traffic signals which operate independently of & look different to the signals used by the general traffic. This gives the potential for priority (such as being allowed to make turns whilst other traffic is held at 'stop signals' or pull away from stop signals in advance of the other traffic) without confusing the other road users.

Sometimes where efficient detection systems are used so that the traffic signal control computers know where the LRV's are, it then becomes possible to create a 'green wave' whereby as the LRV approaches the various sets of traffic signals located along its route they automatically change in its favour. In this way the public transport may not even need to slow down.

When fully effective this ability to influence the signals in its favour should reduce the time spent sitting at stop lights to an absolute minimum, considerably enhancing both the reliability and attractiveness of the passenger transport.


`Amsterdam, Holland: Special 'dot' signals sharing a post with signals for cyclists.`		`Melbourne, Australia: red / amber / white lights in the shape of the letter T.`		`Düsseldorf, Germany: white signals with each aspect being a different shape.`


`Basle, Switzerland: Traffic signals at a three-way junction. See text (below) for detailed information.`		`Looking out the front window of a Stuttgart (Germany) LRV at a traffic signal controlled junction, with an older metre gauge tram waiting in the opposite direction. See text (below) for detailed information.`

Above left Basle, Switzerland. The demands of busy cities make 100% priority impractical, especially where - as here - there are frequent conflicting movements, however it is still possible to give the transport an advantage over the general traffic by allowing it to go first. In this instance the signal for turning left is changing to 'go', when it changes back the coloured signals for the road traffic will then change to green. The illuminated indicator hanging across the junction (see red arrowhead) advises tram drivers in which direction the points are set. This helps ensure they take the correct route!

Above right Stuttgart, Germany. Here station platforms have been staggered on the approaches to the junction, so even if the lights were showing 'go' the vehicles would still have to stop first to allow passengers to board and alight! In this image the special signal is in the form of white lights, (showing 'stop') as seen to the right of the picture. One of the extra signal aspects (not illuminated) will be to inform the LRV driver that the traffic signal computer knows they are waiting there, be patient, the lights will change in a very short while.

There are two short video clips showing some of the traffic signals seen on this page in action...
Projector icon This link is for a 69 second video clip named 'Tram-tsigs1-320.mpg' which shows Amsterdam, Melbourne and Düsseldorf, as seen two rows above.
This link is for a 71 second video clip named 'Tram-tsigs2-320.mpg' which shows sequences from Basle (as above, left;) Toronto, (as several rows below, left;) and a British sequence from Manchester which does not directly relate to any specific still image seen on this page.

More Examples Of Signal Types and Systems.



`Zürich, Switzerland: Where routes diverge there are separate 'white dot' signals for each direction, plus another indication (the orange chevron) advising tram drivers which way the points are set.`		`Amsterdam, Holland: Where routes diverge there are separate 'white (or red) dot' signals for each direction, plus a different type of indication advising tram drivers which way the points are set.`

`This example from Geneva, Switzerland shows a location where there is a side road accessed by traffic turning left across the path of the trams. The red triangle and tram pictogram are marked out with red and amber coloured lights which flash alternately to warn road vehicle drivers to look out for trams. This is easier to see in the clickable larger versions of the images.`

`At a space restricted location in Stuttgart an alternative to restricting the traffic to just a single road lane sees the light rail sharing a traffic lane for a short distance with traffic signals being used to hold back the general traffic and allowing approaching LRV's to continue their journey with minimal, if any, delay. These views were taken in the off-peak period when road traffic was very light.`

`Only one direction of travel needs to adopt this solution. The three-rail trackage seen in these views is because whilst nowadays Stuttgart's system uses standard-gauge light rail vehicles it was originally a metre-gauge street tramway which over a period of years has been rebuilt and upgraded.`

`Toronto, Canada: Two sets of 'normal' signals side by side with a special road sign (Transit Signals) alongside them. NB: Image sourced from S-VHS-C videotape - the clickable larger version is a little fuzzy.`		`British signals at a pedestrian-controlled road crossing in Sheffield, England. These only show 'go' aspects when trams are actually approaching.`

`The Blackpool - Fleetwood interurban line has also been (partially) retrofitted with modern signals, although at this junction the traffic signal planners have got it wrong and used the signals to delay tram services. See text (below) for detailed information. Because of the small size of the signals in relation to an image which needs to show an overview of the location the signals are more clearly seen in the clickable larger image.`		`British signals on the (lower) Great Orme line in Llandudno, Wales. This signal is showing 'go' and as the descending tramcar must cut across the path of the road traffic all the other signals are at red (stop). Clicking this Great Orme Tramway image will lead to a dedicated page showing larger and more images in a popup window; alternatively clicking here will open the page in a new full-size window.`
The picture shown above left from the Blackpool - Fleetwood interurban line was taken at a road junction where the introduction of the new signals has negatively impacted upon traffic flow. Previously the trams would follow the traffic signals used by the general traffic, but instead of continuing with this (perhaps with the trams given a few seconds head start) the traffic signal engineers created an appalling scenario whereby the trams must now wait their 'turn' in the lights' sequence, which here is AFTER! the road traffic. (Apparently they don't have signal pre-emption?) The net result is that the traffic signals take considerably longer to sequence through the various phases - especially as they now also include a separate 'right turn' phase (for vehicles wishing to cross the path of the trams - this in itself being quite reasonable) and therefore journey times are extended, disbenefiting tram passengers and other road users alike. Aren't our road planners wonderful? - maybe they mean well but in their actions they are mis-managing traffic, reducing junction capacities and generally making life less pleasant for everyone. Another specific aspect of (British) tramway operations at traffic signals where the rules have been designed to disbenefit trams and other road users alike comes from a document called Guidance on Tramways - Railway Safety Publication 2 which has been issued by the Office Of Rail Regulation. Ruling 233 states "Two or more trams should not normally operate through a signalled highway junction consecutively, in the same direction, and within the same phase. Any proposal to do so should be discussed with the Inspectorate at an early stage." This document is in Adobe Acrobat format and can be found at http://www.rail-reg.gov.uk/upload/pdf/rspg-2g-trmwys.pdf - link will open in a new window. Dial-up users should note that it is 750kb in filesize. The implication of this ruling is that if two (or more) trams were to bunch - perhaps because they originated from different locations - the second (and subsequent) tram(s) would have to await a completely new phase of the traffic signals at each junction - not only delaying itself but all the other road traffic too. Whilst this ruling could be perfectly sensible on a segregated and fully signalled section of light rail (ie: when operating in railway mode), as far operating on the public highway in 'street tramway' mode is concerned this is sheer madness and simply must either result from desk-bound pen-pushing officials who are so wrapped in their own compartmentalised worlds that they have completely lost the plot as to how road traffic flows or it presages similar time-wasting congestion-causing rules which will prohibit (two or more) buses and heavy lorries from passing through traffic signals in the same direction during a single traffic signalling phase. When Operating In Railway Mode. Many light rail systems also include locations where they use dedicated rights of way which are fully segregated from street traffic in traditional 'railway' mode. Whilst these segregated light rail lines can still operate using the 'on sight' system another option is for the line to be partially or even fully signalled. It all depends on local requirements. Generally though higher speed lines with poor sight lines will feature signalling, albeit perhaps only in the specific areas that need it. For reasons of safety it is usual for all tunnelled sections to be signalled. Level Crossings. Where segregated light rail lines operating in traditional 'railway' mode cross the roadway either traffic signals or traditional railway level crossing type flashing lights can protect the intersection. On higher speed lines or where visibility is restricted lifting barriers are an added safety option.

`Basle, Switzerland. A level crossing on a high-speed suburban tramline guarded with full barriers and flashing lights.`		`Adelaide, Australia. A level crossing on this high-speed inter-urban tramline guarded with half - barriers and flashing lights. This line was originally a steam railway, it was converted to trams in 1929.`

`Tyne & Wear Metro, England. Level crossing protected by railway-style flashing lamps but no barriers.`		`London (Croydon) Tramlink, England. Level crossing protected by traffic signals but no barriers.`

`This crossing at David Lane on the Nottingham NET system must be unique because whilst the light rail is protected by the traffic signals as part of the pre-existing road junction the parallel heavy rail trains are protected by traditional railway flashing lights and lifting barriers.` Complete Separation. At locations where surface crossings would be inappropriate flyovers or flyunders will allow light rail services to pass unhindered in safety. This can apply whether the light rail is operating in 'street' or 'off-street' mode.

`Flyover - Paris, France route T1, over a busy mainline railway.`		`Flyunder - Under a busy roadway in Portland, Oregon USA.`
Pedestrian Crossings. For pedestrians frequent crossing points permit easy access across a fenced track, perhaps with wig-wag flashing lights and audible alarms advising them that a vehicle is coming. For added safety a linked signal can give the LRV driver confidence that these lights are working correctly.

`Blackpool, England. One of the numerous pedestrian crossing points protected by pedestrian operated swing gates. Pedestrians wishing to cross the line must use their eyes - in the same way as they should look before crossing a roadway. However as visibility on the straight section of track is very good, and trams only travel at modest speeds, so maybe this is sufficient to ensure safety.`		`Manchester, England. Flashing 'wig-wag' lights and a fixed sign at an otherwise unsignalled pedestrian crossing. The lights flash alternatively, but in this video-still they have been 'caught' at the halfway stage. Clicking either the image or the projector icon will download a 15 second video clip named 'Tram-crossing-wig-wag320.mpg' showing the action being described.`

A pedestrian crossing point across a line located on a dual-carriageway median in Düsseldorf, Germany. For safety this crossing is fitted with wig-wag flashing lamps which advise passengers when a vehicle is coming (left) and a linked signal (a flashing white light) to give LRV drivers confidence that the pedestrian signals are working correctly (right). NB: Images are sourced from S-VHS-C videotape and the clickable larger versions are a little fuzzy. Clicking either the projector icon or here will download a 21 second video clip named 'D-Dorf-crossing-flashing-lights320.mpg' which shows the action being described. The Blackpool - Fleetwood tramway is a legacy tramline where old practices which were once deemed to be sufficient have been overtaken by changing conditions. Especially at the northern end of the route between Cleveleys and Thornton Gate it has a number of road crossings where visibility is either restricted or even totally "blind", which effectively means that neither tram nor road vehicle drivers can see each other until the very last minute. Ordinary traffic signals (such as seen on Croydon Tramlink, above) would only be an appropriate solution at some of these locations. For the majority level crossing style wig-wag flashing lights (as seen on Manchester Metrolink or on the Tyne & Wear Metro above) coupled with Düsseldorf-style secondary signals (so the tram drivers can be confident that the warning system is working correctly) would be better. However as most of these crossings are in residential areas it is questionable whether audible alarms would be welcomed - especially at night.

Above & Below These four images come from the Broadwater tram stop (on a cold, wet, November afternoon) which is on the cross-country section near to Fleetwood. As can be deduced from the upper pair of images this location is a busy road crossing, which the trams have to 'fight' their way across. The lower images show that the only forms of traffic control here are are a tram road sign (for the traffic) and a road crossing road sign (for the trams). The latter is located on the overhead wire support pole, and to make easier to see has been enlarged as an inset.

Perhaps the most appropriate solution here (which would also cause minimal disruption to the general traffic flow) would be level crossing style wig wag lights. For trams heading towards Fleetwood these would be automatic, whilst for trams heading towards Blackpool & Starr Gate they should be operated by the tram driver, when (s)he is ready to cross the junction. This is because immediately in front of the road crossing are a tram stop and reversing point, so there is no point in the signals working automatically when tram might not be going to cross the junction - plus even on quiet winter days (such as when these four photographs were taken) the delay whilst passengers buy their tickets from the tram driver means that if automatically controlled the flashing lights could be going for several minutes, needlessly creating road traffic chaos.