Last month Viewpoint Vancouver covered how the right hand driver turn on red lights at intersections came about. That movement is a vestigial hold out from a half century ago. During the 1970’s gas crisis it was felt that it was more fuel efficient to allow vehicle drivers to turn right on red lights instead of waiting for the green signal. Prior to the 1970’s the right turn on red was largely prohibited in North America. Today Montreal and New York City are two of the only cities that prohibit drivers making a right turn on a red light. And they are both pedestrian oriented cities.
The right turn on red has persisted even though the Insurance Institute for Highway Safety (IIHS) found over 40 years ago that permitting these right turns by drivers increased driver crashes with pedestrians by 60 percent and increased driver crashes with cyclists by 100 percent.
But what about the driver turning left at an intersection? The American National Highway Traffic Administration (NHTA) has found that 36 percent of all driver crashes at intersections were on left turns, and those turning movements result in twice the pedestrian and cyclist deaths as right hand turns, with three times more serious injuries.
There are three main reasons why driver left turns are dangerous to pedestrians. Vehicle drivers turning left use a wider radius and travel at higher speed, meaning people in the crosswalk are exposed to quick moving vehicles.
Left turns are taken at a wider radius, leading to higher speeds, cutting corners too closely and greater pedestrian exposure. During the left turn, the vehicle driver’s line of sight is not clear, with the vehicle’s A pillar concealing part of the outside view.
Lastly, left turns require more concentration from the driver that may be focussing just on moving the vehicle through a gap in traffic, meaning there is inattention at a moving pedestrian crossing the street.
It was New York City data that showed that left driver turns in the city were causing three times more serious deaths and injuries than right driver turns and in 2014 was one of the first cities in North America to embrace Vision Zero. Vision Zero refers to road design and philosophy that no road deaths or serious injuries occur on the road network.
In a two year study of citywide crash data, New York City in 2018 examined two methods to reduce driver left turn crashes. The first method was the location of bollards and rubber curbs to slow vehicle drivers. While bollards slowed drivers, 40 percent of the bollards were in bad condition and in nearly 40 percent of the intersections the bollards were missing.
The second method trialled was the use of recycled rubber speed bumps guiding the driver left turn at intersections. This decreased driver speed by over 50 percent when making left turns, and resulted in a 20 percent decrease in fatalities and serious injuries. The rubber speed bumps are now used to modify intersections, guide vehicle drivers, and to slow drivers down on left hand turns.
There were some other uncomfortable truths in the data about left hand turn drivers: drivers go faster turning left than right, going 9 miles per hour instead of 5 miles per hour for a right hand turn. It also turned out that seniors with an average age of 67 were most at risk at being killed as pedestrians by left turn drivers. In comparison, all other fatal crash victims had a median age of 50 years.
New York City also found that 18 percent of intersections were responsible for of deaths and serious injuries. Of those intersections, 70 percent of crashes involved drivers on a one-way street, with 80 percent at signalized intersections.
Nearly 70 percent of fatalities and serious injuries happened on roads 60 feet or wider. (Sixty-six feet is the standard width of a Vancouver street to property line.) And 51 percent of left driver turn accidents happened with a minor road going to a major arterial.
You can see in the illustrations below how the rubber speed bumps are used as wedges to guide the vehicle drivers and slow them down on two way streets:
You can take a look at this white paper that identifies how traffic calming left turn drivers saves lives. The paper also looks at other cities that have adopted the rubber speed bumps as guidance systems in intersections.
The intervention has been so successful that this company now produces “kits” based upon different intersection designs to implement the intersectional speed bumps.
Thanks for posting, Sandy. I hadn’t seen too many examples of these newer treatments. They take a beating in Eastern winters but would last longer here. And they’re cheap. Ideal for pilot projects…
In every discussion on left turns I try to make the same point: the A pillars on modern cars are large due to safety and airbag requirements, and during a left turn the blind spot behind that pillar moves at about the same speed as a walking pedestrian, so it’s really easy for a pedestrian to get lost behind it.
To drivers: you need to move your head left and right to get a view around the A pillar in left turns to make sure there isn’t a pedestrian hiding back there.
To pedestrians: if may seem like you’re in plain view, but be aware that a left turning driver may still not be able to see you, so keep an eye on him and be prepared to dodge if it looks like he’s coming your way.