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
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