The problem at Fifth Line and Great Northern Road

It was on the agenda before Saturday's serious car-motorcycle crash that closed Great Northern Road for more than five hours.

But tomorrow night, your City councillors will debate what can be done to improve driver safety at the intersection of Fifth Line and Highway 17 North.

Names of injured released from Saturday's crash

At Council's last meeting on June 14, it was suggested that traffic signals are needed at the intesection.

But Pat McAuley, the City's commissioner of public works and transportation, believes lights are not needed there.

McAuley has re-submitted a memorandum he wrote three years ago, arguing that requested turn restrictions were intoduced in 2001 and he still considers the other conclusions relevant.

The following is the full text of McAuley's 2001 memo:

******************************************************** Subject: Intersection of Fifth Line & Highway 17 North

City Works Centre 128 Sackville Road

01 09 06

Mayor J. Rowswell and Members of City Council Civic Centre

On November 27,2001. Council passed the following resolution: Resolved that the letter from the resident at 238 Landslide Road concerning the feasibility of traffic signal lights at the intersection of Fifth Line and Highway 17 North be referred to the Commissioner of Public Works and Transportation for review and report back to Council.

Background

The intersection of Fifth Line and Great Northern Road (Highway 17 North) is a complex intersection as a result of the difficult geometrics of the two roads involved.

Fifth Line crosses the Root River and leaves the river valley at a 7.5% grade where it meets Great Northern Road at an acute angle.

The highway is on a super-elevated long sweeping curve in this location with extra lanes for deceleration, acceleration, left turns and northbound slow moving vehicles.

The intersection was last reconstructed in 1981 as a M.T.O. highway Connecting Link project.

Improvements to date

Over the past several years. P.W.T. staff has carried out a number of improvements.

These include:

• Asphalt paving to increase the radius for eastbound vehicles on Fifth Line, turning south

• Installation of flashing lights north and south of the intersection, warning highway traffic ahead of time that vehicles are waiting to cross over the highway or make a left turn onto it

• Sight line improvements along the east side of the highway, north and south of Fifth Line. Approximately 100 cubic metres of fill was removed in the fall of 2000 to improve the sight line to the south, and trees were trimmed and brush removed on the north side, for similar improvements to sight distances to the north.

Traffic signals

The letter from Mr. Martin suggests traffic signals are needed to improve the safety of this intersection. According to the Manual of Uniform Traffic Control Devices (MUTCD):

The function of a traffic control signal is to assign the right-of-way between conflicting streams of traffic with maximum efficiency. Maximum efficiency implies the minimum delay and minimum hazard reasonably obtainable. Installation of a traffic control signal, which as the name implies, is primarily a control device rather than a safety device, rarely can be justified as a safety measure alone as its installation does not necessarily guarantee a reduction in accident experience.

Provincial experience has shown that traffic signals may decrease accidents, but at the same time increase delay and user costs.

The reverse can also be true with accidents increasing after signal installation.

Therefore, if a net effect is to be determined, all factors of signal operation must be rated by some common denominator.

A comprehensive warrant rating system has therefore been developed to determine if traffic signals will have a net benefit.

The following information is analyzed: • Physical suitability of the intersection • Accident history • Volume of traffic on each leg • Delays to cross traffic Warrant Analysis

Our analysis has concluded that the intersection is not physically suitable for signals given the profile of Fifth Line.

Vehicles could not proceed safely across the intersection on a green light at a normal speed due to the severe grade imposed by the Root River valley, in combination with the cross fall (superelevation) of Great Northern Road.

In addition, warrants are not met for volumes on the minor street, delays to cross traffic, accidents or in a combination of these factors.

The intersection is also on a sweeping curve of the highway and not readily visible when approaching from the north.

Traffic signals installed here would be the first ones encountered for southbound traffic within several hundred kilometres and need to be readily visible from a distance.

Traffic lights are thus neither feasible nor warranted and therefore not recommended.

We do, however, recommend that a prohibition be put in place for both eastbound and westbound truck traffic, including school buses, crossing over Great Northern Road or turning left.

In our analysis of crossing sight distances, it was determined large vehicles crossing Great Northern Road or turning left do not have adequate sight distances to make these maneuvers safely, given their slower acceleration.

A site distance of 398 metres is required for westbound trucks to make the turn and accelerate, and 317 metres is required for westbound school buses. Only 265 metres are available.

For eastbound trucks, 465 metres of visibility are required and for buses, 334 metres. We measured only 282 metres of available visibility.

Accordingly, we recommend cross over movements and left turns for trucks and school buses be prohibited at this intersection.

All other traffic movements for the various vehicle classifications, including right turns for trucks and buses, were found to have adequate sight distances.

With these prohibitions, truck and bus traffic generated on Fifth Line wishing to cross over or make left turns at Great Northern Road will need to travel south and use Fourth Line as an alternative.

If Council is in agreement, appropriate signs will be installed and the affected trucking firms and bus companies will be notified of the restriction.

Traffic By-Law 77-200 will be revised accordingly.

Patrick M. McAuley. P. Eng. Deputy Commissioner Public Works and Transportation

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