Why Hanover Posts Roads
One of the first signs of spring (besides frost heaves) is the seasonal posting of roads. Why do we do we post roads and how does it affect me?
As the weather warms and snow begins to melt, frost in our roads begins to thaw as well. In a typical year frost isn’t completely out of our roads until the middle of May. There are some roads such as the gravel portion of Reservoir Road which still has frost in mid to late June. Roads thaw from the top down causing melt water from snow and rain to saturate the materials in the roads above the frost. If the soil material in roads base have excessive fine material (silts and clays) the road loses strength and ruts may form. This is very common in gravel roads since many of them were constructed over native material which are generally high in silts and clays. Some of our paved roads suffer from the same issue of poor base materials and will rut as well under heavy loads.
Gravel roads can be regraded once the ground thaws, but paved road surfaces will break and need to be rebuilt if this occurs. Roads can become so rutted, particularly gravel roads, that they will be impassable. The cost to regrade is < $0.10 per square yard of road surface, while a pavement rebuilt is on the order of $50-$100 per square yard.
Generally, cars and vehicles under 3 tons don’t cause much damage to roadways. However, one loaded 80,000 dump truck or tractor trailer has the same effect of 9,000 cars! By keeping vehicles over 3 tons off some of our roads until the frost as fully thawed, road surfaces can be preserved much longer.
Certain vehicles are exempt from this restriction, particularly school buses, emergency & public works vehicles and fuel trucks. Public works use lighter vehicles when possible and we require contractors working for the Town to put lighter equipment on posted roads. If you need a deliver of something other than fuel, there is a process that we can give permission on a day to day basis depending on the weather and road. For information contact 643-3327 between 7:00 – 3:30.