Why can I see tire marks in my new driveway?
Some facts about your new driveway or parking lot.

In 1987 the Federal Government initiated the Strategic Highway Research Program (SHRP) in an effort to improve the performance and durability of the nation’s highway system.  One of the problems SHRP identified with the existing system was the inability of the liquid asphalt binder being used to withstand the temperature ranges in many areas of the country.

As a result of this study, we now have a PG (Performance Graded) binder system to ensure that the asphalt being used is appropriate to the climate.  Asphalt is now modified to withstand pre-determined temperature ranges.  SHRP also established a nationwide weather database to determine the 7-day average highest temperature and the 1-day lowest temperature for every area of the country.

The asphalt in use in southern Maine prior to the SHRP study was suitable for a temperature range of 147° F to - 8° F.  The weather database showed us that, while the high temperature was fine, the asphalt should be able to withstand a minimum low temperature of -18° F.  That would increase the flexibility of the pavement in cold temperatures to help reduce cracking.

Based on these studies, the Federal Highway Administration and the Maine Department of Transportation mandated the use of a new softer, more pliable asphalt for all of their projects. Since the majority of the liquid asphalt sold in Maine is used on State highway projects, and asphalt supplier storage space is limited, this new asphalt is the only one currently available to Maine contractors.

Unfortunately, this new asphalt results in a slightly softer pavement that is more susceptible to marking, particularly in driveways and parking lots and in warm weather.  While unsightly, most of the marking is superficial and rarely results in any real structural damage.  After a few months of curing, the marking should stop and any marks left should be ironed out by traffic.

On a positive note, this creates a surface that is more resistant to cold weather cracking, which should extend the life of your new pavement.  Cracking is a major cause of pavement deterioration.  Cracks allow water to seep into the pavement and gravel base causing a great deal of damage, particularly during freeze / thaw cycles. 

You should be aware that neither this nor any other new pavement can eliminate reflective cracking on re-surfacing projects.  Reflective cracking is when the new pavement develops a crack directly over an existing crack in the old surface.

We also recommend you wait 4 to 6 months before sealing your new pavement to allow proper curing.