Safe Speed Forums

Camera partnerships frequently claim a greater improvement in pedestrian accidents (or casualties, or KSI etc) than they do for other accident types.

One example is the (stinky) report of the two year pilot:

http://www.safespeed.org.uk/twoyear.pdf

Contains:

"In the six pilots, there was a 35% reduction compared to the long-term trend of the number of people killed or seriously injured (KSI) at camera sites during the first two years."

and

"The reduction in the number of pedestrian KSI casualties per annum is highly encouraging. At camera sites, there was a 56% reduction."

Just recently I have been asking myself about the possible mechanisms for the difference in claims.

* We know that there's a regression to the mean error, but why would regression to the mean apply differently to pedestrian accidents?

* We know that walking (pedestrian traffic if you like) is tending to reduce, but a quick estimate does not appear to suggest that the reduction in walking is sufficient to explain the difference in the claims.

* We have to consider that it might be due to the reduction in traffic speed, but why would a reduction in traffic speeds benefit pedestrians more than other vehicles? I have looked at speed / fatality relationships for different road user types and it doesn't make sense to me that pedestrians benefit more, but I can't actually eliminate the possibility at this stage.

I'm starting to think that speed cameras benefit pedestrians in their location by increasing pedestrian fear of traffic. It stands to reason that a speed camera sends a very loud (and distorted) message to pedestrians about the dangers of traffic. We know that pedestrians are responsible for most pedestrian accidents - so the first place to look for an improvement is in pedestrian behaviour.

Anyone else got any theories, or suggestions about how these ideas can be tested?

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

Vehicles are designed now with a pedestrian impact in mind. Gone are the days of solid metal bumpers.

This must of had an effect.

The only way to reduce pedestrian death, is to deal with the root cause. That is pedestrians, it is now seen as driver error or speed when a pedestrian steps out in front of a car.

There should be more emphasis on the pedestrians responsibility for crossing roads in a safe manner.

The advert that was regulary run on TV showing a vehicle in an out of control skid impacting with a jay walker in a built up area. Only blamed speed, no mention of the pedestrian at fault.

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Steve

I'm just thinking out loud here, Paul. You've suggested yourself that some cameras may have been credited with reductions that are really due to engineering. Is it possible that some of that engineering might be benefiting pedestrians more than vehicles. Maybe a new camera has been put up at the same time as a barrier on the kerb, so pedestrians simply aren't crossing the road at that point anymore. Also, regression to mean at some locations might favour pedestrians if the typical accidents there in the past were car vs. pedestrian. Not too sure how to go about checking any of this out though.

maybe one way would be 'jay walking' charge if within 10m of a crossing or something. As if I hit a pedestrian, even if they are dancing in a road or whatever, its my fault for not seeing them...

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uzz

Do not have theory - do not have many scameras in my patch anyway - and we have lowest incident rate in the UK!

Visiting relatives in scam hot spots ( Wales, Lancs, Cumbria, Cambs ) - cannot help but notice that - in addition to a scamera - there is steel barrier erected at the kerb as well. The only place they can cross is via subway or pelican crossing. This would contribute much towards pedestrian safety and accident prevention.

Also - noted that some scameras along dual carriageway are not roads on which you would find many pedestrians j-walking anyway - so again this must impact on the stats provided.

Also pedestrian will perceive speed cam as warning sign and perhaps be a little more aware. You have to remember - we are all pedestrians and we could just be hitting the brakes in our legs as well when we see a camera!

Coud it be that out of the total number of unwise pedestrians there is always a stable proportion of those that happen to run out into the road right in front of a car (alternatively the driver prefers to watch his speedo rather than the road ). This then leaves the driver with little or no time to react . Thus the unwise pedestrian's injuries in this particular case are a function of the free travelling speed and are in proportion to the 4th power of this speed? Even a small reduction in average vehicle speed should then benefit these (unwise) guys.

If the above is correct then speed cameras have a positive effect, locally. It may be that if the speed cameras were replaced with electronic warning signs the positive effect would be tripled? Who knows. This would not be enough to convince me that overall speed cameras benefit us. To deny the existence of side effects without doing any studies comes across as a little disingenuous so I will reserve my judgement for now.

arthurdent

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DO NOT PANIC

I think there is normally a press release or something that goes with the camera so peds are made more aware of the danger of the road via local press. I think this is exactly why we are seeing more problems now that 20 zones have been increased. Due to the safe feeling peds have to crossing without looking.

It realy is time for peds to be held more responsible for their actions. While I am an advanced driver (whatever that means) I am the worst pedestrain. I'm always exercising my right of way (crossing side roads etc) without thinking that it realy doesn't mater who's at fault if I'm hit.

I also have to say that the number of drivers who don't realise that they will normally be liable if they hit a pedestrian is huge.

Many drivers think they have right of way over peds when turning into side roads.

Problem is that that is only one part of the story. Yes, a reduction in free travelling speed might reduce injuries for this particular type of pedestrian, but speed cameras don't achieve that effect in isolation (if at all). We also need to consider...

1. Any decrease in speed local to speed cameras will also be accompanied by a decrease in observation, as drivers are distracted by additional speedo checks at this critical moment, so a lower free travelling speed might actually lead to higher impact speeds. For example, a car travelling at 30mph with the driver just beginning a speedo check will actually take longer to stop in response to a hazard than one travelling at 44mph but with the driver watching the road. This is based on the highway code figures plus an assumption of 0.7 secs for a speedo check - though Paul's recent research actually puts the figure at more like 1 second, worsening this effect.

2. The presence of a camera may actually lead to a false sense of security in pedestrians, leading to more of them stepping blindly into the road, mistakenly believing that the camera will ensure that cars are now travelling slowly enough not to be a problem.