To reduce the number of bicycle falls around Luas tram tracks rubber inserts into tracks are likely only a suitable solution for a small number of high-risk locations and focusing on education is unlikely to be effective alone. A new study by Trinity College Dublin researchers instead suggests street redesigns as the main solution.
The study is the first of its kind to use computer-aided video trajectory and fall analysis to plot the direction and type of falls across tram tracks.
The paper, ‘Computer vision-based assessment of cyclist-tram track interactions for predictive modeling of crossing success’, was published last month in the Journal of Safety Research. It was compiled by TCD researchers Kevin Gildea, Daniel Hall, Clara Mercadal-Baudart, Brian Caulfield, and Ciaran Simms.
The authors said that their analysis focuses on weekdays, and peak commuting hours. They said that while initially, their sample included both dry and wet conditions, “a significant preliminary analysis found no falls during dry conditions” and that previous research shows that “Wet road conditions are a significant factor for cyclist falls on tracks.”
As previously reported, the researchers found that people cycling being forced into crossing Luas tracks at shallow angles increases the risk of falling. Authorities should “encourage crossing angles of 60 degrees or more ideally 90 degrees”.
Researchers found that 92% of unsuccessful crossings of tracks “involved obstacles that limit crossing angle, ie, kerbs or nearby/passing vehicles/other cyclists. Many cases involved passing/nearby motorised vehicles…”
This led the authors to recommend that “physical separation of cyclists from tram tracks be prioritised, and at locations where cyclists are expected to cross tracks, sufficient space should be available for safe approach and exit angles.”
This includes segregated cycle paths and, in some cases, relatively simple adjustments of kerbs. One of the suggestions is using jughandle-shaped turns for people cycling to line them up at close to 90 degrees to the tracks.
The researchers said that authorities should also look at track design modifications including the positioning or alignment of tracks, reducing vehicle traffic and speeds in urban areas with tram tracks, and rubber/plastic rail fillers.
Regarding track inserts, however, the researchers warn: “There are effectiveness and feasibility concerns. One potential issue is that the fillers may not fit perfectly into the gap between the tram tracks and the road surface, which could lead to other safety issues.”
Such inserts might be mainly a viable solution in areas with a high risk of cyclist falls or where there is a large volume of cycling traffic such as at College Green. But even at that, the researchers say that “further assessment is required.”
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At Westmoreland St./College St. failed crossing of the tracks was due to the proximity of a kerb and also likely influenced by traffic pressures, and the curvature of the tracks. The crossing angles at this location were on average 17 degrees vs. 43 degrees overall. The authors suggest that this could be improved by widening the space available at this location to “allow for safe crossing angles would likely have a significant effect” on the number of unsuccessful crossings.