CITY TRAFFIC ENGINEER'S REPORT
ISSUE NO. TC 500
(Left Turn Restrictions on SW Greenway at the Driveway Near Hall Boulevard)
November 13, 2002
Background Information
Near Hall Boulevard, Greenway runs in a north-south direction. Vehicles going away from Hall are southbound. Those going toward Hall are northbound. On Greenway approximately 250 feet south of Hall there is a major driveway serving the parking lot of the adjoining Albertson's grocery store. At the driveway location, Greenway has one lane southbound and two lanes northbound.
The City has received numerous complaints about left turns into Albertson's driveway during afternoon peak hours. A southbound vehicle waiting to turn left at the driveway blocks the southbound lane. During the afternoon peak, left-turning vehicles sometimes cause the southbound traffic to queue into the Hall intersection. The queuing causes further reduction in the capacity of the Hall/Greenway intersection. The Hall/Greenway intersection experiences significant capacity problems. During the weekday afternoon peak, westbound traffic on Hall may queue to Creekside Drive or beyond, eastbound traffic may queue to near the top of the hill, and northbound traffic on Greenway may queue beyond the Albertson's driveway. The long traffic queues are caused primarily by lack of capacity on Greenway.
There is also concern about the potential for rear-end collisions at the driveway. Due to the curve in Greenway, it is difficult for southbound motorists to see a vehicle stopped to wait for a left-turn opportunity. This is a greater issue during peak hours when the wait for a left turn opportunity is often a long wait.
The Albertson's parking lot has an alternative access from Hall Boulevard east of Greenway. The Hall driveway provides good access for vehicles approaching on Hall. However, the manager of the Albertson's store indicates that delivery trucks need to use the Greenway entrance in order to be able to back into the store's loading dock. Due to truck restrictions and a low bridge to the south, trucks must approach the Greenway driveway southbound from Hall.
In order to address the capacity concerns, staff recommends that parking be prohibited on Greenway at the driveway from 4 p.m. to 6 p.m. on weekdays. The prohibition is recommended only during the peak hours in order to maintain truck access to the store during most of the day.
Applicable Criteria
Applicable criteria from Beaverton Code 6.02.060A are:
1a (provide for safe vehicle, bicycle and pedestrian movements);
1c (meet the overall circulation needs of the City);
1g (carry anticipated traffic volumes safely).
Conclusions:
1. Restricting left turns will reduce the potential for rear-end collisions on Greenway at the driveway and will reduce the conflicts between left-turn traffic and northbound traffic, satisfying Criterion la.
2. Prohibiting left turns during peak hours will reduce restrictions to traffic capacity on Greenway. Limiting the prohibition to peak hours will allow the needed truck circulation during the remainder of the day. The proposal is a compromise to satisfy the circulation needs per Criterion 1c and to improve the ability of Greenway to carry peak hour traffic volumes safely per Criterion 1g.
Recommendation:
Between the hours of 4 p.m. and 6 p.m. on weekdays, prohibit left turns from southbound Greenway into the commercial driveway located approximately 250 feet south of the Hall Boulevard intersection.
Issue TC 500
City Traffic Engineer's Report
