Asphalt roads get their strength from the quality of the subgrade, base course and asphalt layers. The subgrade and base course are layers with varying degrees of manufactured gravels. Subgrade has very little manufacturing and is generally made up of natural soils, that are good for road building, mixed with some uncrushed rock. Compacted well, it helps support the base course and asphalt. Base course is manufactured and, when compacted well, it helps to support the asphalt layer while allowing water to drain away from the pavement and subgrade. Complete reconstruction involves removing the existing asphalt, base course and subgrade and reinstalling with new material. 

Water is the biggest challenge in the health of a road. Over time, when the pavement cracks, water can weaken the base course and subgrade. When the layers beneath the pavement get weak, the pavement breaks up under the traffic load and that’s what is happening on 19 Street. Complete reconstruction will provide new subgrade and base course to support the brand-new pavement.

Because 19 Street sees a lot of traffic, the pavement structure is deep: almost 1 metre in some places. The contractor will have to remove the existing material and replace it with new material. To keep things dry, the contractor works in small sections, ensuring that they don’t have long sections of roadway open allowing water into the subgrade when it rains. 

During peak traffic volume times, some traffic movements experience significant delays at this intersection. In 2020, the overall intersection delay was 30 seconds. A project team explored various options to solve this issue. One option was to add lanes to the existing signalized intersection, this option resulted in 31 seconds of delay. The multi-lane roundabout option resulted in 6 seconds of delay.