March 11, 1999

To:Chairman and Members of the Scarborough Community Council

From:Gary H. Welsh, Director, Transportation Services, Works and Emergency Services, District 4

Subject:Proposed Modifications to Traffic Control Signals - Lawrence Avenue East at Crockford Boulevard and Ellington Drive, Scarborough Wexford

Purpose:

To investigate the feasibility of incorporating the intersection of Lawrence Avenue East and Ellington Drive into the traffic control signals at the intersection of Lawrence Avenue East and Crockford Boulevard.

Funding Sources:

Not applicable.

Recommendations:

It is recommended that this report be received for information.

Council Reference/Background/History:

At the request of Councillor Norm Kelly, staff have investigated the feasibility of incorporating the intersection of Lawrence Avenue East and Ellington Drive within the existing traffic control signals at Crockford Boulevard in response to concerns that the subject intersections are not fully signalized, which restricts access to Lawrence Avenue East.

Comments and/or Discussion and/or Justification:

Currently, the 'T' intersection of Lawrence Avenue East and Ellington Drive is not signalized. Ellington Drive is controlled by a stop sign at Lawrence Avenue East and continues north from that point. The signalized 'T' intersection of Lawrence Avenue East at Crockford Boulevard is located approximately 30 metres to the west, and Crockford Boulevard continues south from Lawrence Avenue East. The resulting configuration could be described as a "Near-Right", partially signalized offset intersection.

There are inherent safety and operational problems associated with offset intersections, the worst of which are normally found at fully signalized offset intersections. A common solution to mitigate these concerns is to signalize only one of the intersections (as in this case) and to prohibit some of the left-turn movements at the other. At the subject location, eastbound left turns from Lawrence Avenue East to Ellington Drive are prohibited from 7:00 a.m. to 9:00 a.m., and 4:00 p.m. to 6:00 p.m., Monday to Friday. Similarly, southbound left turns from Ellington Drive to Lawrence Avenue East are prohibited during the same periods. These prohibitions have been in effect for over twelve years.

The safety concerns associated with a "Near-Right" fully signalized offset intersection, which would occur if the Ellington Drive intersection were incorporated into the existing traffic control signal, are briefly described below:

1.Difficult to Establish a Clear Right-of-Way

A motorist's ability to establish the right-of-way within the intersection is impeded because of the series of manoeuvres necessary to complete a through movement between Ellington Drive and Crockford Boulevard.

Specifically, traffic must first complete a right turn from Ellington Drive, followed by a left turn from Lawrence Avenue East onto Crockford Boulevard. As a result, traffic turning left onto Lawrence Avenue East from Crockford Boulevard cannot distinguish between opposing through traffic (westbound on Lawrence Avenue) and opposing traffic which has turned right from Ellington Drive. Therefore, if the subject intersections were fully signalized, motorists on Crockford Boulevard may turn left across the path of through traffic from Ellington Drive (destined to Crockford Boulevard) which they have mistakenly interpreted as turning right (destined westbound on Lawrence Avenue East). A similar problem may arise for motorists turning left from Ellington Drive.

2.Increased Potential for East-West Rear-End Collisions (Unnecessary Stopping)

Traffic turning right on green from the minor street would face a red traffic control signal on Lawrence Avenue East. Although this signal is intended for main street traffic, some minor street traffic would stop within the intersection. In doing so, motorists risk being involved in a rear-end type collision.

As a result, we would anticipate a potential rear-end collision problem involving northbound and southbound right turns from Crockford Boulevard and Ellington Drive, respectively.

3.Potential Increase in Pedestrian-Related Collisions

The offset between Ellington Drive and Crockford Boulevard would require that the north-south crosswalks be located approximately 60 metres apart. This spacing would allow minor street traffic turning right onto Lawrence Avenue East sufficient distance to accelerate prior to crossing these crosswalks. This would result in Lawrence Avenue East traffic crossing the north-south crosswalks at speed and right angles to the direction of pedestrian travel, even though the pedestrians would have proceeded on a "walk" indication.

It cannot be assumed that, by including the non-signalized intersection into the traffic control signals, the total number of collisions at the intersection would be reduced. Instead, the collision potential which exists for the left-turn movement onto and from the minor street would be replaced with an increased collision potential for minor street through and left-turn movements, rear-end type collisions, and collisions involving pedestrians crossing the arterial road.

The Toronto Police Service collision records for the five-year period ending December 31, 1997 indicate that there were eleven collisions which involved southbound vehicles turning left onto Lawrence Avenue East, and one which involved an eastbound vehicle turning left into Ellington Drive. Of the eleven southbound collisions, three occurred during the afternoon peak period when southbound left turns are prohibited.

Further to the concern that the subject intersection does not allow residents sufficient access to Lawrence Avenue East, alternative routes are available for traffic destined to eastbound Lawrence Avenue East from Ellington Drive. Specifically, traffic originating from Ellington Drive may also turn left from Ainsdale Road. We recognize that this routing may be a little inconvenient for motorists. However, in the vicinity of Ainsdale Road, Lawrence Avenue East consists of a five lane cross-section including a centre two way left-turn lane. The proximity of the traffic control signals located at Crockford Boulevard provides gaps in westbound traffic, which facilities easier egress for southbound vehicles from Ainsdale Road.

Conclusions:

Although incorporating the subject intersection within the traffic control signals at Crockford Boulevard may reduce delay and improve convenience for traffic turning left onto Lawrence Avenue East from Ellington Drive, it would create significant new safety concerns at the intersection which would place the public at greater risk compared with the existing operation. Furthermore, the existing intersection operations and road network in the immediate area provides for reasonable access to eastbound Lawrence Avenue East.

Contact Name:

Andre R. Filippetti

Supervisor, Traffic Investigations, District 4

Telephone: 397-5017

Fax: 397-5011

E-mail: afilippetti@cclink.metrodesk.metrotor.on.ca

Gary H. Welsh

Director, Transportation Services

Works and Emergency Services

District 4

ARF:ca