Tuesday, June 17, 2008

Traffic Light at Wai`anae High School

From: Brennon.Morioka@hawaii.gov
Subject: Fw: Questions for DOT from Waianae Neigh Bd. Mtg
To: maileshimabukuro@yahoo.com
Cc: Alvin.Takeshita@hawaii.gov
Date: Tuesday, June 17, 2008, 6:43 AM

Hi Maile - Here is more information on the traffic light at the intersection of Farrington Hwy and Waianae High School as to whether the crosswalk and left turn signal be simultaneous rather than consecutive? Comment was that it's an unnecessary delay since the crosswalk falls beyond the turn into the school.

What you are asking is possible, but is not recommended by national highway safety guidelines. While it is true that there is no pedestrian/vehicle conflict, the concern that exists is with motorist expectations based on their normal experience with other similar intersections which then influences their driving behavior and choices. Normal operation of signalized "T" intersections do not allow pedestrians to cross with an opposing left-turn movement and motorists are conditioned to expect it to operate this way because that is how it is everywhere else. And we know that driver conditioning plays a large role in the decisions they make consciously or unconsciously. To have an intersection that operates under different conditions violates a motorist's expectation which may cause confusion and increases the likelihood of possible accidents.

The classic example is in Kakaako where there are a bunch of all-way stop controlled intersections, but there is one which is only a two-way stop. You see two types of driver behavior at this intersection:

1. Motorists who don't have a stop, slow down because they think they have a stop and
2. Motorists who do have a stop, assume that the conflicting approach also has a stop, so they proceed into the intersection thinking that the conflicting

What may happen in this situation is that motorists going Makaha bound on Farrington Highway may see the left-turn traffic going into the school and assume that they too have the right-of-way (green) because that is how other intersections operate. Yes, they would be breaking the law by going through a red signal, but our concern would be for the instance that this happens and someone is crossing in the crosswalk at the same time.

Hope this helps.

Brennon Morioka, Director
Department of Transportation

[See the earlier posting, "Traffic Update - Maile's Q&A with DOT"]

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