Wednesday, November 16, 2022
Questions over Welsh Government's 20mph limit plan
It is fair to say that the Welsh Government's plan to introduce a 20mph speed limit as the default on all urban roads is controversial. There are genuine questions about how it is going to be enforced, and whether it is really necessary away from schools and accident blackspots. Their rationale though is that reducing speeds increase safety, and so far, that argument has not be challenged.
There is a report on the wales-on-line website however, that research by Queen's University Belfast has found that reducing speed limits to 20mph has "little impact on road deaths or crashes".
Researchers say that while the lower limits lead to quieter streets with fewer cars, they have "little impact on long-term outcomes including road traffic collisions, casualties and speed":
The research looked at roads in central Belfast before, one year after and three years after 20mph speed limits were introduced in 76 streets in the city centre in 2016. They compared the data with city centre streets where the restrictions didn't apply, as well as streets in the surrounding metropolitan area and similar streets elsewhere in Northern Ireland that had all retained their speed limits of 30-40 mph.
They found that a 20mph speed limit was associated with little change in short or long-term outcomes for road traffic collisions, casualties, or driver speed. Specifically, they found crashes were reduced between three and 15% after one and three years but there was no "statistically significant" difference over time.
Casualty rates fell by 16 and 22 per cent one and three years after implementation, but these reductions "weren't statistically significant." Average traffic speed fell by only 0.2 mph one year and by 0.8 mph three years after roll-out.
The most significant findings was the reduction of vehicles on the roads. During the morning rush hour between 8am and 9am there were 166 fewer vehicles a week compared with similarly matched streets where the 20 mph speed hadn't been applied.
A decrease in traffic volume of 185 fewer vehicles a week was also found when comparing all sites before and three years after roll-out.
Study author Professor Ruth Hunter said: "Previous research has suggested that 20 mph speed limit interventions should be supplemented with other interventions such as driver training, social marketing, community engagement, closed-circuit television (CCTV), in-car interventions, community interventions (eg, speed watch), and police communications.
"Such success may then have the capacity to facilitate an ambitious culture change that shifts populations away from the car-dominant paradigm and help us recognise that 20 mph speed limits are not simply a road safety intervention, but instead part of the fundamental reset of the way we choose our life priorities-people before cars.
"Our findings showed that a city centre 20 mph intervention had little impact on long-term outcomes including road traffic collisions, casualties and speed, except for a reduction in traffic volume.
"Future 20 mph speed limit interventions should consider the fidelity [enforcement], context and scale of implementation."
This research casts doubts on claims that the new default speed limits would save Wales £100m in the first year from less medical treatment needed because of fewer crashes. They claim that the cost savings alone are a "gross over-simplification and underrepresentation" of the health benefits of the lower speed limit, although studies have shown a 20mph limit encourages more walking and cycling, therefore improving physical and mental health.
Perhapsx the Welsh Government need to go back to the drawing board.
There is a report on the wales-on-line website however, that research by Queen's University Belfast has found that reducing speed limits to 20mph has "little impact on road deaths or crashes".
Researchers say that while the lower limits lead to quieter streets with fewer cars, they have "little impact on long-term outcomes including road traffic collisions, casualties and speed":
The research looked at roads in central Belfast before, one year after and three years after 20mph speed limits were introduced in 76 streets in the city centre in 2016. They compared the data with city centre streets where the restrictions didn't apply, as well as streets in the surrounding metropolitan area and similar streets elsewhere in Northern Ireland that had all retained their speed limits of 30-40 mph.
They found that a 20mph speed limit was associated with little change in short or long-term outcomes for road traffic collisions, casualties, or driver speed. Specifically, they found crashes were reduced between three and 15% after one and three years but there was no "statistically significant" difference over time.
Casualty rates fell by 16 and 22 per cent one and three years after implementation, but these reductions "weren't statistically significant." Average traffic speed fell by only 0.2 mph one year and by 0.8 mph three years after roll-out.
The most significant findings was the reduction of vehicles on the roads. During the morning rush hour between 8am and 9am there were 166 fewer vehicles a week compared with similarly matched streets where the 20 mph speed hadn't been applied.
A decrease in traffic volume of 185 fewer vehicles a week was also found when comparing all sites before and three years after roll-out.
Study author Professor Ruth Hunter said: "Previous research has suggested that 20 mph speed limit interventions should be supplemented with other interventions such as driver training, social marketing, community engagement, closed-circuit television (CCTV), in-car interventions, community interventions (eg, speed watch), and police communications.
"Such success may then have the capacity to facilitate an ambitious culture change that shifts populations away from the car-dominant paradigm and help us recognise that 20 mph speed limits are not simply a road safety intervention, but instead part of the fundamental reset of the way we choose our life priorities-people before cars.
"Our findings showed that a city centre 20 mph intervention had little impact on long-term outcomes including road traffic collisions, casualties and speed, except for a reduction in traffic volume.
"Future 20 mph speed limit interventions should consider the fidelity [enforcement], context and scale of implementation."
This research casts doubts on claims that the new default speed limits would save Wales £100m in the first year from less medical treatment needed because of fewer crashes. They claim that the cost savings alone are a "gross over-simplification and underrepresentation" of the health benefits of the lower speed limit, although studies have shown a 20mph limit encourages more walking and cycling, therefore improving physical and mental health.
Perhapsx the Welsh Government need to go back to the drawing board.
