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The Hazards of the Left Turns

Left turns are hazardous.  Every licensed driver in every right-side drive jurisdiction in the world knows this instinctively and as a matter of learned driving skill.  Is it even possible to go through modern life without seeing an intersection crash involving a left-turning vehicle or, at least, the aftermath?  Apart only from the ‘fender-bender,’ left turns that ‘go wrong’ are a ‘crash cliché.’ And the fault, typically, is on the part of the left-turning driver.  (An oncoming driver “running a red light” is a notable exception)

Car with a left turn

Pedestrians are also a subject

Add a pedestrian crossing into the mix and things get even trickier for all road-users, and, given the hierarchy of vulnerabilities, it should be said —‘especially for the pedestrian’. Intersection speeds tend to be in the lower range but also involve acceleration.  Every extra kilometer-per-hour bit of speed adds extra force to the turning vehicle aiming directly to also cross the path of oncoming pedestrians.

Of course pedestrians should only be moving into or in that crosswalk when they have the clear right-of-way.  Most signal-controlled intersections include pedestrian controls, but pedestrian flow is unpredictable and irregular, to say the least.  They dart at the last minute, they dawdle, and they seem blissfully unaware of their vulnerability as if painted lines on asphalt somehow provide a bulletproof barrier.

Repeat: left turns are dangerous

Good drivers—skillful, seasoned drivers—know this. They know that left turn across a lane of oncoming vehicular traffic that also parallels a pedestrian crosswalk still involves ongoing assessment of the traffic in both the oncoming vehicle lane and the pedestrian crosswalk— from both directions.

It bears repeating: left turns are hazardous.  Because of this, much of the hazard —the attempt to estimate the speed of oncoming traffic, whether or not there is sufficient time to cross the open oncoming lane and the pedestrian crossing—has been almost wholly eliminated at major ‘arterial’ intersections by dedicated left-turn pull-out lanes controlled by an advance-green-arrow lighting sequence that clears the intersection of turning vehicles in advance of those straight crossing.

10, 9, 8, 7, 6…

The green arrow is paired with a pedestrian “DON’T WALK” signal. The only tricky part is estimating the end of this sequence, and whether or not there are unpredictable pedestrians at the curb. In jurisdictions where left-turn pull-outs are common —they are ubiquitous for instance in the Palm Springs ‘cities’ in California, the light cycle is long, and both drivers and pedestrians get impatient.  Frustration then high acceleration rates – a bad emotionally influenced combination.

But there are still many ‘capillary’ intersections where left-turning remains a matter of careful calculation, and where the degree of hazard is easy to underestimate.  Road Rules was recently reminded of this in a typical recent story.  Two cars, one waiting to left-turn into the eastbound lane and one stopped in that lane to allow a waiting pedestrian to cross.  All three made eye contact.  The pedestrian stepped into the crosswalk …and then the turning driver accelerated into the turn.  The unfolding was nightmare-like. Avoiding disaster was a matter of centimeters not covered.  It ended in seconds.  Hearts were pounding. “I didn’t see you!” said the ever-so-sorry left-turning driver.  Easy mistake to make.

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Road Rules by Cedric Hughes and Leslie McGuffin

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