Cyclists win first two cases following Edinburgh tram track falls

Noting the report on the recent success of claimants for injuries sustained on Edinburgh tram tracks. As an engineer, whose first experience if working on railway tracks was in 1968, with this linked to building cycle paths, and perhaps the first 'cycle-scale' cattle grids, I've been involved in designing out the risks delivered when tram tracks, and other steelwork is embedded in pavements - largely road carriageways, and the closely related, highly skewed level crossings.

When the Nottingham Tram system was being planned (20 years ago), I worked with HMRI and Nottingham's Pedals group, to help the project team deliver what, at the time was track to the best standard possible. This drew on the long established standards from the 1870 Tramways Act, still underlying modern tramway bills, plus the remarkably consistent set of height limits (and profiles) for vertical 'steps' in highway pavements - 3mm for slippery ironwork, tar sealed joints and thermoplastic markings, 6mm for paving slabs, dropped kerbs, railway level crossing surfaces, tactile paving ridges (this being tested by TRRL with cycle tyres hitting the ridges at an oblique angle, when whetted with a water-detergent solution). The basic result is delivered in the diagram used for the ORR guidance for tram track design (illustration P7), and the quality of the transverse profile we delivered for NET Phase 1, still, after nearly 20 years, in good order. 

Studies of Edinburgh, and Toronto casualties, return some consistent detail. Around 70% of the falls arise when the front tyre is rotated on the 2 smooth edges of the flangeway groove and drops into the slot , which is exactly the right width (c 35mm -tapered) to lock the regular town bike tyre (37mm) size solid, and bring the bike to an abrupt halt. This will happen especially when the cyclist is crossing the rails slowly, and is unable to resist the force turning the handlebars. More on this later, but perhaps counter intuitively, crossing the rails faster, with a firm control of the steering reduces the risk of this happening.  A further 20-25% of crashes are caused by the tyres sliding sideways along the 2 smooth edges, as the tyre contact patch (approx 120mm long) is not bridging to high friction pavement either side of the rail. These crashes happen when crossing at all angles, when the rider is turning or braking, and putting a side force on the tyre.

By comparison its worth noting the case of Roe vs Sheffield Supertram, where car driver lost control and crashed, where it was found to be the height of the rail, projecting over 3mm above the road pavement, formed a key causal factor in this case. From new, Edinburgh's on-street track has been well adrift from the ORR's standards for transverse profile, delivering not just a flangeway groove to tackle, but the 2 poured seals (which shrink, detach from rail & pavement, and get ripped out by bus tyres) plus the lumps coming loose & falling out of the concrete track slab, where it has cracked and is rocking through ground settlement, with the tyre 'snatching' holes and steps where the tarmac and other pavements abutting the concrete have moved and sunken down , and the manhole/valve chamber ironwork which continues to sink - requiring a repair every 6-9 months. It was interesting that no reference was made to the Roe case, despite it being very clear that the transverse profile of  the embedded rail on the Edinburgh system leaves much to be desired, in comparison with that in Manchester, Nottingham and Blackpool.

Edinburgh tracks were being laid contemporous with work in Blackpool and Manchester, and it was noted at the time, that there was a massive difference in the quality of the work, as I've recorded in Albums for my Flickr account (A V Lowe). Manchester's team, are now consistently delivering embedded tram rails with high friction concrete finish, precisely 2mm higher than the abutting rail and its thin rubber insulating boot, leaving only the flangeway slot and smooth rail to deal with. Contrast this with the ploughed field effect that the rails present to cyclists in Edinburgh.  No surprise then that Manchester has fewer crashes.

There's also a further cause of Edinburgh's problems, which started with the need to fix the track on Princes Street before trams had even started running - the original design had tarmac right up to the rails' rubber 'boots' . Tarmac is effectively a very thick 'fluid', and this arrangement, rapidly moved away from the rails leaving big slots, cracking, and with chunks falling out. So the whole job had to be re-done mainly with black-coloured concrete extending out to the edge of the buried track slab, and some tram-only areas laid with stone blocks - which have sunk, come loose, and broken in various places. Manchester had similar problems with the original street tracks, and clearly the lesson was learned - the new contracts provide for the sub-grade, on which the track slab is laid, to have minima for ground strength (California Bearing Ratio = 15 or better), and cohesion (Vane test). The Manchester works anticipated measured remedial work, if the required ground conditions were not met.

Edinburgh's track is laid on a 'beach' with a bed of fractured shale below this, and it is 'wet' - the railway tunnel under Scotland Street struck wet (running) sand on its way to Waverley.  To build the track, the streets, with around 200 years of compaction, and a load spreading construction system of stone setts - very probably on a puddle clay bed - the C18th equivalent of a geotextile membrane, were stripped and material removed. The cracking of the finished track slab, and sinking carriageways suggests that there may be some issues with the ground beneath the pavements and track slab, in addition to the poor transverse profile of the embedded rails.

There is also a system which has totally eliminated cyclists' falls on railway crossings since 2005, and has delivered this in the UK since 2014 (Cycling writer Roger St Pierre's brother being a victim on the first UK crossing to get the system before it was fixed). Unfortunately this system can only be used with main line railways (BR113A vignole rails), and would need to be designed in from the start - on a new tram line - or a VERY expensive job on an existing route, built with lighter, and smaller tram-section rails... I was involved in bringing this to the UK and the first location on a popular road club circuit on the A684 near Bedale, where it eliminated at least one hospital/RIDDOR call every month, for a 'broken cyclist'.

A second option to mitigate the classic falls seems possible, by removing one of the 2 smooth edges on which the cycle tyre can slide. I've done some preliminary work, and demonstrated the tyre-slide effect, with Birmingham Cyclists, but as yet no one has come forward with support to test this in the field. It could be done initially (with a cheap but less robust high friction tape - as used by British Cycling to treat manhole covers for road race circuits) on the over-run tracks at York Place in Edinburgh, or perhaps the currently closed off track at Stephenson Street in Birmingham, or the new/rail renewal works in Trafford, Sheffield, and Croydon. It might last 2-6 months with traffic running over it, based on what I've seen in use.

Ultimately a solution of complete rebuild of the carriageways between Haymarket Terrace and St Andrew Street, might be better addressed by aligning with many other European cities and putting the route underneath Princes Street, extending this back to Haymarket if possible. This would resolve many compromised details, both in of the siting of tram stops, the interaction with motor traffic, the issues for cyclists, and the problems with the track & carriageway pavement, which are visible and obvious from the many cracks, sunken areas & repairs that have been made.

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That looks dreadful- not sure how it's supposed to work with cars, yet alone bicycles.  And what does 'footpath closed due to crushing zone with tram' mean?  Is it normal for trams to include 'crushing zones'?  It looks as if they've just forced a tram line in there and decided to hell with all other transport modes.

The opposite: the building works on the left are new(ish) - certainly newer than the tram tracks - so while they're building whatever it is, the footpath is closed and people are told "don't walk down the side of the construction site because if a tram is coming it will pin you against the side".

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That said, here's an example of "vastly superior" in Manchester:

Cycling - there is actually a waymarked cycle route (I guess the equivalent of a London Quietway) just before that point, on Todd Street. Takes you down the side of Cathedral Gardens rather than across the 4 lanes of tram tracks at Corporation Street.

I didn't say it was perfect - there are plenty of bits that I look at and think - hmm, that's a bit of a fudge. But given that it's nearly 100km of line and has been running since 1992 (albeit on a far smaller scale than now), it's still got a much better safety record with cyclists than the Edinburgh line which is 1/10th the size and has only been operational for 4 years.

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To be honest, I dislike trams.  They all seem like vanity projects to me.  Probably pushed by that 'monorail' guy out of the Simpsons.

The major problem with them is if there's an incident or accident along one of the lines and there have been many case of fuckwitted motorists blindly following a tram from a road-running section into a segregated section and then getting stuck on the rails and needing their car lifted off and then the rails need checking...

Which means no trams along the entire line until all that is finished, it's not like a bus where you can just say "turn left here, cut out that bit of road and re-join it 100m further along".

On the plus side, they're much faster than buses, zero emission and you can fit more people on them.

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Perhaps it should have been considered at the planning stage, but hey, only cyclists..

Planning?! Ha. Edinburgh Trams was one of the most badly planned and implemented infrastructure builds in the UK - several years late and about £775-million (double the estimated cost) for a single 9 mile tram line. A litany of cock-ups, political arguments, contractual disputes and heavy public criticism dogged it at every stage. The tracks along Princes Street failed not long after installation (crumbling tarmac where the tracks were inlaid) and some genius came up with the idea of a cobbled trackbed which had to be dug up and replaced after objections from cycling groups about safety. There were lots of objections rasied during construction and becasue of the political arguments around it all and the massive delays, none of them were listened to and the result is this - the council having to pay out yet more money in compensation for incidents that should never have happened.

Manchester Metrolink managed to build nearly 100km of track for not much more than that, on time, on budget and while it's far from perfect with regards to cyclists (there was one cyclist death in 2016), compared to Edinburgh it's safety record is vastly superior. It can be done properly with a bit of thought at the design stage. Edinburgh had none of that.

I'm guessing, and I'm quite happy to be corrected, is that these are just painted cycle lanes, if at all, thus leaving the cyclist with the choice of the messing with dangerous vehicles or the risky tracks.  It might seem that the cyclist was an afterthought with the layout of the system, with motorists impatiently passing the riders and not understanding the extra room needed when negotiating tracks.

Maybe the answer would be a fully protected route which would the cross the tracks at a relevant angle, seperated from the motor vehicles.  Perhaps it should have been considered at the planning stage, but hey, only cyclists..