There have been many reports of motorists using the lack of traffic on the roads during the Covid19 lockdown to flout the speed limits and now with more traffic back on the roads there is a danger that some may continue to drive at excessive speeds even after things are back to ‘normal’.
Behavioural Science in transportation (understanding the behaviour and motivations of transport users such as motorists and rail commuters etc) is a fascinating subject which plays a big part in the engineering and design of roads and their ‘furniture’ in an attempt to gently persuade drivers to modify their driving behaviour to something more appropriate.
There are many such psychological tactics in place to combat speeding but could we be doing more? What other engineering solutions could be implemented to stop excessive speeding? How do different countries tackle speeding on their roads? What could we learn from them?
. . . An example of a 50 mph speed calculation and a second response time:
50 mph ⇒ 5
5 * 1 * 3 = 15 meter response distance
More accurate method: Calculate response distance
Formula: d = (s * r) / 3.6
d = response distance in meters (to be calculated).
s = speed per hour.
r = response time in seconds.
3.6 = Fixed figure for converting km / h to mph.
. . .
I have no wish to question the integrity of Benyamin's long and detailed analysis. However it can be expressed very simply.
Thinking distance in feet equals speed in miles per hour.
For braking distance in feet, divide speed in miles per hour by 20, square it, then multiply by 20.
Example: 50 mph.
Thinking distance is 50 feet. (Very close to Benyamin's calculation of 15 m)
50 divided by 20 is 2·5. 2·5 squared is 6·25. 6·25 multiplied by 20 is 125, which is braking distance in feet.
So overall stopping distance is 175 feet.
A table showing braking distances based on this simple calculation used to be published in the Highway Code for many years. Unfortunately in recent issues this has been messed up my the Government's half-baked approach to metrication. Mixing imperial and metric units always complicates things.
If we were to do a thorough job, I am sure that we come up with an equally simple calculation of stopping distances in metres based on speed in km/h.
. . . An example of a 50 mph speed calculation and a second response time:
50 mph ⇒ 5
5 * 1 * 3 = 15 meter response distance
More accurate method: Calculate response distance
Formula: d = (s * r) / 3.6
d = response distance in meters (to be calculated).
s = speed per hour.
r = response time in seconds.
3.6 = Fixed figure for converting km / h to mph.
. . .
I have no wish to question the integrity of Benyamin's long and detailed analysis. However it can be expressed very simply.
Thinking distance in feet equals speed in miles per hour.
For braking distance in feet, divide speed in miles per hour by 20, square it, then multiply by 20.
Example: 50 mph.
Thinking distance is 50 feet. (Very close to Benyamin's calculation of 15 m)
50 divided by 20 is 2·5. 2·5 squared is 6·25. 6·25 multiplied by 20 is 125, which is braking distance in feet.
So overall stopping distance is 175 feet.
A table showing braking distances based on this simple calculation used to be published in the Highway Code for many years. Unfortunately in recent issues this has been messed up my the Government's half-baked approach to metrication. Mixing imperial and metric units always complicates things.
If we were to do a thorough job, I am sure that we come up with an equally simple calculation of stopping distances in metres based on speed in km/h.
