Spring and Summer Safety

Road construction can create frustrating travel delays. Unfortunately, most of the highway work can only be done during spring and summer where there are periods of good weather. As roadbeds thaw in the spring, potholes, surface breaks and cracks are common on our highways. These breaks in the road are caused by the freezing and thawing of water below the surface of the road.

During the spring and in wet conditions, crews work to ensure the highway is safe and passable. More permanent repairs are completed when the subsurface has dried out.

The ministry maintains more than 26,000 km of provincial highways so there can be many work zones across Saskatchewan during construction season and motorists are reminded that flag persons work to make sure everyone gets through the workzone safely. Working on the highway can be a dangerous job, so please respect the people working in these highway construction zones.

Spring Road Failures

Potholes form when the surface of the road collapses into the subsurface. This is caused because of Saskatchewan's cold, harsh climate. When water freezes, it expands and causes the pavement to bend or crack, weakening the road. When ice melts, the pavement contracts leaving holes in the subsurface where water can get in. If water freezes and thaws over and over, the road can become very weak.

Sometimes potholes do not appear until the weight of traffic, especially loaded commercial trucks, has passed over the weak spot in the road.

Vulnerable Highways

Some paved highways are more vulnerable to potholes and surface breaks than others. Typically, aged and cracked roads will allow more water into the subgrade. Roads with lower structural capacity and grades stay saturated longer until the road has had a chance to dry out.

Thin Membrane Surface (TMS) roads can be very sensitive to spring break-up. These highways do not have a "granular structure" under the surface. It is not a structural asphalt concrete. A TMS road is designed as a dust-free surface and not designed to handle heavy traffic. If loaded commercial trucks travel over TMS roads with a saturated subgrade, surface breaks are expected. If more trucks travel on the road when the subsurface is weak, more damage will occur.

Typically, an above-average spring runoff and a high water table can make conditions worse. Dry weather helps stabilize the roadbeds and allows crews to make repairs.

Highway Repairs

When surface breaks occur in the spring, crews place red diamond signs at the hazard and assess the type of repair that is needed. The crew may apply gravel material or blade on some asphalt patching material as a temporary repair until more permanent repairs can be completed.

Small potholes will be filled with patching material. Long-term repairs at spot failures may involve digging out the road and backfilling with well-drained sand or gravel that will support the pavement and keep water from building up.

A layer of asphalt concrete or a granular seal coat will be placed on top of the backfill to seal off the road.

Selecting the type of repair and whether it will be a permanent or temporary fix depends on a few different factors:

Highway classification.
Surface type.
Overall condition of the road.
Age of the road.

Roads scheduled for major rehabilitation work may not receive long-term repairs.

Timing of Repairs

Timing of temporary repairs will depend on how much repair work is scheduled and type of spring. Crews may be busy unblocking culverts from debris and ice to ensure proper drainage during the spring to avoid unnecessary flooding and road washouts. If a long-term repair is needed, then they may wait until the area dries up before starting the work.

Crews prioritize their work based on the type of highway and severity of the failures.

Definitions for Maintenance Treatments

Spot Seal – Applying liquid asphalt and graded crushed rock on roads to stop moisture from entering the subgrade and prevent further deterioration. Strip sealing is done in ruts to prevent the moisture from sitting in the ruts.
Deep Patch – Digging into the sub-grade with a machine and backfilling with well-drained sand or gravel.
Machine Patching – Spreading base gravel or asphalt mix with a grader or other machine to repair a failed area, wheel ruts, depressions, bumps, etc.
Crack Sealing – Sealing of cracks on a pavement with liquid asphalt and sand or rubber asphalt.
Gravel Blading – Reshaping of the road surface and spreading of crushed rock on gravel highways by blading with a grader.
Spot Gravel – Defects on gravel roads can be fixed by spot re-gravelling.
Dust Treatment – Applying different dust suppressant products on a gravel road to control dust.
Hand Patching – Repair of small potholes by filling with cold mix, hot mix or base material and packing.
Sub-grade Stabilization – Clay, silt, or gravel is used to steady sandy subgrades or to cover rough road surfaces on gravel highways.
Sandvik Blading – Removes or recycles the asphalt from the surface with a grader, which is done to improve the ride by smoothing out the ruts on TMS surfaces.
Micro-surfacing – Crushed gravel, liquid asphalt, mineral filler, water and other additives are mixed and applied to the road surface. This can be used for both preventative and corrective maintenance. It helps restore skid resistance and eliminates minor surface bumps, levels wheel ruts which prevents hydroplaning and prevents further surface deterioration from weather and traffic. Micro-surfacing restores pavement to a uniform black colour.
Seal Coating – Hot liquid asphalt and crushed gravel on the road surface. Seal coating provides a waterproof surface, non-skid surface, reduces deterioration and cracking and prolongs pavement life.