Reducing truck speed may be counter productive
Researcher believes lowering truck speeds to 90km/h could be more dangerous than using a mobile phone while drivingRuza Zivkusic-Aftasi | March 20, 2012
A 90km/h speed limit on trucks could be more dangerous than driving while talking on a mobile phone, a researcher says.
John Lambert and Associates Director John Lambert says a 20km/h speed differential between a truck and average traffic speed has eight times the risk of a crash.
"That’s twice the much publicised four-time increase in crash risk for mobile phones," Lambert says.
He has responded to Victorian Transport Association’s (VTA) decision to look at the feasibility of a 90km/h speed limit on trucks similar to the policy Ryan’s Freighters has adopted.
"If Ryan’s wants to do the right thing they would use GPS to implement and enforce a 90km/h limit in 100km/h zones, while allowing their trucks to do 100km/h 110km/h zones," Lambert says.
He believes a large sample size of trucks and a lengthy trial is necessary to prove whether a reduction in speed limits will improve safety.
"In order to show a change in crashes you’d need to be looking at probably a minimum of 20 crashes before and 20 crashes after the change to speed limits," Lambert says.
"Any study aimed at proving a safety gain from a 90km/h limit would require either a very large number of trucks – say 500 trucks with crash records for two years prior to the same 500 trucks monitored for another two years, or a very long trial."