On the railway or the tramway, safety is paramount – more important than anything else.
If there are trespassers on a railway line, trains will run slowly until offenders can be dealt with. If a
truck hits a railway bridge, the line will be closed until engineers can verify that it is safe, even if it means delaying passengers. And if an accident does happen, it will be investigated in great detail to identify the causes and to ensure that – as far as humanly possible – it cannot happen again. As a result, after 180 years of gradual improvement, rail travel has become the safest method of land transport.
In the United Kingdom, tramways come under the same safety authority and accident investigation regime as the mainline railway. The difference is that, while railways operate in a controlled environment, tramways operate in streets, town centres, and parks, where they encounter pedestrians and other road users whose movements are outside an operator’s control. It is therefore essential that tramways are designed and operated to minimise the risks of interactions with traffic and pedestrians.
Launch of the COST Action
In 2011, two French tramway professionals, Laëtitia Fontaine of national cableway and guided transport safety authority STRMTG (Service Technique des Remontées Mécaniques et des Transports Guidés), and Dominique Bertrand of the Government mobility research institute CEREMA (Centre d’études et d’expertise sur les risques, l’environnement, la mobilité et l’aménagement), were concerned about accidents between tramways and other road users in France.
To share knowledge and expertise across a range of safety issues, they invited tramway partners from across Europe to participate in a collaborative research project. With support from the EU-funded COST initiative1, they agreed to set up a study programme and COST Action TU1103, Operation and safety of tramways in interaction with public space, was born at an inaugural meeting in Brussels in September 2011.
Participants in the Action were transport professionals – operators, authorities, researchers, consultants and academics – from all the major European nations. Representing the Confederation of Passenger Transport and UKTram, I joined as one of two UK representatives, along with tramway consultant Tony Young.
Objective of the Action
Trams are a fundamentally safe mode of transport, but it has to be recognised that any accident has a big impact. The objective of the Action was to gain a better understanding of safety issues by managing trams’ interaction with other road users. By sharing and combining potential solutions across European cities, the study aimed to propose some practical answers and ultimately to minimise tram accidents and their impact.
Reducing accidents is self-evidently a good thing, but it also has the wider benefits of reducing the costs of repairs and disruption, decreasing maintenance and operating costs, helping vulnerable users and improving efficiency and reliability. Ultimately this helps to optimise tramway investments, encouraging public transport use and moderating the dominance of the car.
Following the first gathering, the initial working meeting took place in Bordeaux in March 2012, followed by two to four meetings each year in different host cities. Tony Young and I organised one such meeting in Manchester, with the generous co-operation of Transport for Greater Manchester.
These meetings consisted of plenary sessions on aspects of tramway safety and progress meetings of the participating Working Groups. Each included a technical visit to the tramway in the host city to study how different cities approach safety issues, and some included a visit to a system in another nearby city – for example, to Graz from Vienna, to Plzeń from Prague, and to Blackpool from Manchester.
Identification of accident hotspots
The first task of the study team was to identify the main accident ‘hotspots’ on a tramway, to identify where efforts should be concentrated. This cannot be done from official statistics as each country has its own methodology for gathering data, and tram accidents are not identified in sufficient detail to do any meaningful analysis.
Instead, a semi-structured questionnaire was used to ask operators which locations on their networks were considered at most risk from the point of view of accidents or interactions with other road users. It asked:
1.What are the three safety hotspots in your network? What types of risks or accidents occur, and at what sort of location (junctions, traffic signals etc)?
2.What corrective measures were implemented? Were the consequences positive or negative? Were there any side-effects? Were any measures considered, but rejected, and why?
3. Are there other points in the network which, despite having few accidents, are considered risky? Were any measures considered, and with what result?
4. Were there any success stories – locations that were hotspots but no longer?
Each Action participant interviewed two tram operators in their own country. In the UK we obtained valuable information from the Safety Officers at Manchester Metrolink and Sheffield Supertram. In all, 89 hotspots were identified in 22 cities across 13 countries.
The results of the questionnaires showed that 72% of accidents noted occurred at road junctions, with a further 13% at roundabouts and 15% on running sections (between stations, junctions and pedestrian crossings). The main accident locations were grouped into five interaction points for further study:
• Road junctions involving a left turn (right turn in UK and Ireland) across the tramway
• Pedestrian crossings
• Stops and stations, and pedestrian routes to them
• Pedestrian areas
For each of these interaction points, the analysis employed the methodology below:
Interaction point analysis
The first step was to list in a table, for each interaction point, all the configurations of road and track layout which might apply. For example, at a road junction the tram tracks might continue ahead or turn either left or right, and might go from a central alignment to another central alignment or to the side, and so on. A multitude of configurations is possible, and each brings its own set of hazards to trams, road vehicles, pedestrians and other road users.
For each configuration the table lists the range of hazards which might be encountered (for example, potential collision between tram and left-turning vehicle), the objectives for overcoming each hazard
(for example, to make road users aware of the tram or to prevent left turns), followed by a series of possible mitigation measures that were drawn from the experience of study team members.
To illustrate this methodology, consider the example of the junction at Holt Town, Manchester, where the tramway diverges from the A662 Ashton New Road:
• Configuration: Tramway diverges from the roadway onto a segregated section.
• Hazard: Road vehicle entering segregated off-street tramway instead of following the road.
• Objective: To make drivers aware of the correct course and prevent them driving onto the tram tracks.
• Measures taken: Prohibition signs, warning signs, road markings, unsuitable surfaces (grass, deterrent paving or ballast).
• Reference: The Reference column gives examples where these hazards have been identified and measures implemented, with photographs or diagrams (see left).
In this way, tables of practical solutions found to work in various countries were developed for each configuration of the five interaction points. The study’s final report contains over 50 pages of tables.
Results for stops and stations
Some of the results for the stops and station interaction points (the terms are used interchangeably) are presented here.
A stop or station is a fixed location where passengers may board or alight from a tram, with or without raised platforms. These locations are of particular interest as they are often the point of first contact between users and the system, and are where passengers who want to access the tram service must mix and interact with other people and road traffic in the vicinity.
The following configurations were identified:
• Located centrally in the roadway (between the opposing flows of traffic), or laterally (at the side of the roadway)
• Locations in mixed traffic or segregated from road traffic
• Stops might have dedicated platforms (usually raised to facilitate level access), or passengers might board from or alight into the roadway (a common feature in countries with older tramways).
This gives a number of configurations to be studied, for each of which we must consider passengers waiting at the stop, crossing the road or the tracks to reach or leave the stop, and road users in the vicinity. Some 40 potential hazards were identified at stops and stations; a few examples are presented here.
Firstly, consider passengers waiting at a stop. People waiting for a tram might fall onto the track or step onto the track to wait. This carries the hazard of being hit by an approaching tram. The objective is therefore to make the track uncomfortable for pedestrians to stand on, and to ensure the platform provides sufficient space. The measures taken are, firstly, to use awkward materials between the rails, such as ballast or anti-trespass paving, and, secondly, to widen the platform to cater for peak demands.
Next, consider passengers crossing the tracks from one platform to the other before boarding or after alighting. The hazard is people not seeing another tram approaching, especially if they cross behind the tram they have just left. The objective is to prevent passengers crossing the tracks.
A number of measures have been used by different European systems. In Lyon, guardrails were installed as a physical barrier to prevent people crossing the tracks. This is effective, but may give rise to other risks if people try to scale the barrier, or use an unauthorised crossing. In Porto, extra ‘Danger – Do not cross’ signs were placed on the edge of the opposite platform, in Portuguese and English and coloured red to signify danger. These were supplemented by green signs directing passengers to an alternative, safe crossing place (see page 374, top right).
The dangers are obviously greater when people must cross a road to reach a stop. The hazard here is using a pedestrian crossing without checking if a tram or car is approaching. The objective is to make people aware of the different priorities for pedestrians, trams and road traffic, and the measures used include warning signs, pedestrian traffic lights and road markings – but ‘zebra’ markings are best avoided in order to differentiate roads and tracks. A good solution, illustrated on page 375 in Sheffield, is the kind of offset crossing with separate signals for the road and the tramway.
An interesting solution for protecting passengers from road traffic is shown in Wien (Vienna), as seen above. The Austrian capital has a traditional tramway with street tracks, so passengers wishing to board or alight have to cross a lane of traffic. This creates a hazard of passengers getting hit by a road vehicle in the driving lane. Preventative measures that can be taken are constructing the stop to make it clear where passengers have priority.
The footway is extended as a raised surface into the roadway; passengers see the raised area as part of the footway so can approach the tram confidently, and it also provides a platform edge to assist with boarding. At the same time, the raised surface creates a speed control ramp for road traffic, with additional road markings and signs to show that passengers have priority.
The third category of danger points concerns road vehicles moving around a tramstop. The hazard here is in overtaking a tram at a station and being hit by another tram or a vehicle coming from the other direction. The objective is to prevent road vehicles overtaking when the tram is at the stop. The available measures are roadway markings and signage to deter incorrect car movements, or using infrastructure to prevent such actions. Above right we see an example from Wien: a ‘cape’ extends the platform to the edge of the track, leaving no room for overtaking. To avoid conflicts with cyclists, some cities locate a cycle lane behind the stop so there is no interaction with the tram.
• At junctions, left turns across tram tracks (right turns in UK and Ireland) are common risk points, and the objective is to avoid or control movement by making road drivers aware of the priorities. Measures include traffic signs and signals, road islands and markings, left turn lanes, making vehicles approach the tracks perpendicularly, and staggering the stop line.
In Porto, accidents at a junction were reduced when left turn movements were prohibited or controlled by signals. In Dublin, visibility at a road junction was much improved by removing timber hoarding to improve sightlines.
• At roundabouts, car drivers focus on their exit and may fail to see trams approaching from the other side (see main image on page 373). As a general rule, the study advised against tram routes crossing roundabouts, unless there are strong reasons, in which case it is important to use signs and signals to make drivers aware of the danger.
In Tenerife, accidents were reduced by installing traffic signals on the approaches to a roundabout.
• At pedestrian crossings, the objective is to make people aware of the presence of trams, to provide information about priority rules, and to protect them from trams and other road traffic. Pedestrians are vulnerable road users, but at the same time are difficult to constrain; they walk at random and prefer to cross by the shortest route, and this must be taken into account and a proper balance found.
In Milan, guardrails direct pedestrians so that they can see an oncoming tram. In Stuttgart, Z-formation crossings direct people, first parallel to the track with a view of oncoming trams, then diagonally with a view of the opposite direction.
• At stops, the main hazard comes from passengers and other pedestrians crossing the tram tracks or the road to reach the platforms, or from passengers waiting on a crowded platform where they might fall into the path of a tram or a road vehicle.
• On running sections – including segregated track, mixed zones and pedestrianised areas – mutual visibility, perception and good information are key factors.
In Geneva, red-and-white collapsible posts prevent cars entering the tram path. In Montpellier, cars, trucks, and two-wheeled vehicles driving through a crowded pedestrian area forced tram drivers to make frequent emergency stops. The solution was to reduce the tram speed from 20km/h (12.5mph) to 10km/h (6.25mph), resulting in a decrease in incidents.
While behaviour, legislation and culture vary, the international COST Action TU1103 network proved to be an excellent way to open minds to experiences and good practices.
Recognising the value of this interchange, the team continues to meet annually as the Urban Tram Forum to discuss safety and related matters. Successful meetings, now with representatives from Israel, California and Australia, have been held in Lyon, Dublin and Brussels, thanks to the generosity of transport authorities in those cities.
Images courtesy of the author and COST
Action partners unless stated.
Article appeared originally in TAUT 1005 (September 2021)