Thursday, 30 January 2025

Speed Cushions - Dangerous, Costly, Ineffective!

 

"Speed Cushions" are traffic-calming humps that are installed in sets of (usually) two or three across the width of a road.

They have a number of disadvantages compared to full-width road humps:
1. They are ineffective at reducing vehicle speeds.
2. They result in drivers trying to avoid the cushion by positioning their vehicle wheels either side of it. In doing so they often take a road position that endangers oncoming cyclists, pass too close to cyclists and/or swerve dangerously.
3. They tend to break up more frequently, causing road defects that are especially dangerous to cyclists.

In summary, cushions arguably increase road danger rather than reduce it. And they are expensive to install and maintain! Speed cushions are a choice made in willful ignorance of the problems they cause for cyclists.

Looking at speed cushions in Dorset Road SW19, many are in the process of breaking up. In the image below you can see several recent repairs to a cushion (one small patch on the left corner nearest the camera), but these are very temporary and the cushion is already breaking up again.
 
 


An argument often made in favour of speed cushions is that they allow emergency vehicles to travel faster along a traffic-calmed road, compared to other vehicles. However with the increase in delivery van and SUV numbers, and the increase in width of cars in general, they now have little speed-reduction effect on many private vehicles. It should be noted that road traffic collisions make a significant proportion of ambulance service's workload, so compromising safety with ineffective traffic calming is hardly in that service's interest. Furthermore, the concern about emergency response times does not seem to extend to actually doing anything about traffic congestion or obstructive parking on roads like Dorset Road. At Merton Cycling Campaign we are very much in favour of enabling better emergency response times - and that means tackling congestion. Unfortunately, Merton now has the WORST decline in bus speeds of ANY London borough over the last decade - which is a clear indication of how congestion in the borough has been ignored as an issue by both the Council and TfL - to the detriment of both bus and emergency vehicle speeds.

We call on Merton to immediately cease the use of speed cushions, and replace them with standard sinsoidal (cycle-friendly) road humps that are durable and effective at their intended purpose of reducing traffic speeds. This will make the roads safer for all, and will reduce the cost of road maintenance.
Furthermore, the amount of traffic on roads like Dorset Road really needs to be reduced. Rat-running on this type of residential road puts up the cost of road maintenance - and bear in mind the Council is under severe budgetary pressure.