Monday, March 8, 2010

Division and Sprague: Dangerous by design?

Division is the major four-lane one way arterial going North. Sprague is a major four-lane arterial two way.

These major arterials cross beneath a railroad viaduct, which passes diagonally overhead.

There are no bicycle lanes or shoulders, not even a sharrow. The design encourages motorized traffic to move quickly down the arterials.

Support columns for the viaduct divide the lanes, and obscure vision, in all directions.

Note the proximity of the crosswalk and left turn lane.

Also note the wornout crosswalk and stopline paint (meant to be a solid line, see the undated Google street view.) Also note the use of paint, rather than a more durable and/or lighted crosswalk design.

The one-way configuration and lack of visibility produces ideal conditions for the "left cross" type of collision. The left cross is a well-known accident pattern where left-turning cars strike pedestrians or bicycles in the crosswalk.

Vehicles exiting one-way Division on the viaduct's left lane immediately turn across the barely marked crosswalk. It's probably not surprising that an inebriated driver would make his first misjudgment here. The design allows no margin for error and poor sight lines while encouraging speed.

Left cross conditions are a design feature at many Spokane intersections. For another stunning example, see the two(!) left turn lanes in front of the downtown Public Library (Lincoln turning onto Main)--a crosswalk often used by kids, the elderly, the disabled and just about all of us.

Spokane's choices in street design increase the efficiency (speed) of motorized traffic flow.

At a price paid by non-motorized traffic?


rory said...

I can understand the concern regarding the intersection, especially following a tragedy, but I would like to point out a couple of things to think about regarding this post. This is not defending the driver or city, but just things to think about before pointing fingers.

this intersection has a 1-way arterial crossing a 2-way arterial. Believe it or not, this is safer then a regualar intersection, since it doesnt have as many potential collisions points as a regular 2-way/2-way intersection. From the post, the main concern is the left-turn from division onto sprague.

I have not read the accident report, and do not know about the details of the collision, like what direction the cyclist was going, and what the vehicle driver was doing. I am assuming from your description the cyclist was crossing Sprague against the direction of traffic, or with the traffic in the far left lane or from the crosswalk. From personal experience of being hit by a car in a similar situation(luckily surviving), i would say that either method to cross sprague is not necessarily the best judgement on the cyclist part. the best way to cross Sprague would be on the right side, with traffic, since that's what drivers are use to seeing and expecting cyclist to be. If a cyclist is wanting to go onto division, then either merge with traffic or dismount and use the crosswalk as a pedestrian. this depends on the cyclist comfort.

from your description, i could only see 2 possible solutions, both not conventional and not apparent when the intersection would 1st be designed:
remove the crosswalk on the left turn side
make the crosswalk a separate phase that goes when a person pushes the button.

both of these solutions would depend on the amount of pedestrians(not cyclist) using the crosswalk. if not too many pedestrians currently use the crosswalk, then remove the crosswalk. if there are a lot of walkers, add a separate phase for them.

another thing to think about from the post is:
"It's probably not surprising that an inebriated driver would make his first misjudgment here."

I think the first misjudgement happened when the driver got behind the wheel.

Unknown said...

The white paint is in better shape than some crosswalks I've seen. From what I understand blinking lights, etc. in crosswalks are disfavored as a safety solution in most situations. That being said I hope the crosswalk is studied and all viable alternatives considered.

Anonymous said...

Thanks for the comments.

Quick note to Rory:

"I think the first misjudgement happened when the driver got behind the wheel."

I agree, my wording is misleading.

I didn't mean to diminish the role of alcohol in impairing judgment, including impairment of the decision whether to drive.

The first lapse in judgment may be deciding to drive, but the first outward sign of impaired judgment is often an accident and/or broken law.