Abstract Manager

The Ministry of Transportation, Ontario (MTO) released a new policy memo SCB-HDO-2022-02 on June 27, 2022, which states that the default design speed (DS) for new divided freeways is 130 km/h. On major capital rehabilitation or reconstruction freeway projects, the desirable design speed for divided freeways is 130 km/h.

Parsons evaluated 130 km/h DS on multiple divided freeway projects, such as:

• Highway 400 Widening from Langstaff Rd to Major Mackenzie Dr (MTO Central Region);
• Highway 17 Twinning from 4.0 km west of Bruce Street to 1.2 km east of Scheel Drive (MTO Eastern Region); and
• Highway 69 Expansion from 1.7 km north of Highway 529 (north junction) to 3.9 km north of Highway 522 (Northeastern Region)

Incorporating 130 km/h DS on divided freeways will have an impact to, but not limited to:

• Freeway Geometry (Horizontal and Vertical Alignments);
• Interchange Ramp Geometry, including Speed Change Lanes;
• Cross Slopes and Superelevation;
• Clear Zone and Roadside Safety Devices; and
• Sight Distances.

The key challenging aspects of implementing 130 km/h DS on divided freeways are:

• Environmental Impacts;
• Property Impacts;
• Cost Impacts;
• Constructability Impacts; and
• Complexity of a Core/Collector System, if applicable.

Highway 400 in the Greater Toronto Area is one of the busiest and most congested freeways in Ontario. Given the urban area, the allowable space to widen or realign the existing freeway is limited as the property comes at a high premium. This constraint is common across all freeways in urban area. Highway 17 and Highway 69 are located in rural areas, where environmental impacts may be more significant than property impacts.

Whether the freeway is existing or new will have a significant impacts on the feasibility of implementing a 130 km/h DS. New freeways have more flexibility in the design with less cost impacts. Existing freeways are more challenging because the cost to implement 130 km/h is much greater as constructability becomes challenging.

For each of the projects noted above, the design team reviewed existing design elements, compared it the design standards for 130 km/h DS, developed the concept/preliminary design incorporating the design standards for 130 km/h DS within the constraints of the project, and reviewed the impacts. When certain design elements cannot be designed to 130 km/h DS, safety impacts become a key factor to review.