Recently I have been reading the new NACTO Global Street Design Guide, in it is this great graph that illustrates the power of speed & it’s effect on the risk of pedestrian death after impact.
As you can see at 60km/h the risk of pedestrian death after impact is near 90%, at 50km/h it is around 60%. What is amazing is what the graph shows is a drop of just 10km/h can make a huge difference to the safety of our streets. Reducing a 50km/h local street to 40km/h reduces the risk percentage by 35% to 25%.
Now we can start to understand why many places around the world on local streets have reduced speeds to 30-40km/h.
The guide recommends that Shared Spaces be 10-15km/h, Urban Streets be 40km/h, while Local Streets 30km/h
The guide also recommends protected cycle lanes for streets over 30km/h.
We have seen the NZTA recently come up with a new Speed Management Guide (Post by Matt with more information) on speeds which move much closer to the NACTO recommendations which Neighbourhood Streets & Town Centres recommended at 40km/h & CBD’s/Town Centres with a concentration of active users 30km/h. Lets hope that these guidelines are approved legislatively & filter down making our streets safer for people, as well as much more welcoming.
So in my humble opinion I will sum up my post in one meme “The Speed Limit for Local Streets in Auckland is too Damn High”