If Contractors Just Built Roads to Last Longer… 30 to 50-year design life and CPM

When the Michigan Legislature passed a long-awaited transportation funding increase in 2015, a “lockbox” was tied to some of the funds requiring the state to evaluate 30-year and 50-year pavement design standards.

Those projects are moving forward with the hope that innovative new techniques and processes will extend the service life of pavements.

While Michigan roads are traditionally built with a 20-year design life, preventive maintenance treatments have been used for many years to make these roads safe and serviceable for 30 to 50 years, or longer, depending upon a variety of factors including traffic volumes.

Even when a road is constructed with a very costly 50-year design, preventive maintenance is the key to achieving the 50-year lifecycle.

The Autobahn – the benchmark for road longevity – benefits from pavement preservation techniques. The same micro surfacing process used in Michigan today was tested and perfected on the Autobahn, adding a new wearing course to improve ride quality and extend pavement life on this iconic system.

All roads, from the Autobahn to the interstate, county roads and city streets, need preventive maintenance to remain safe and serviceable.

The use of the right treatments at the optimum time for a road’s condition is the most cost-effective way to achieve a 50-year lifecycle for Michigan roads.

Based on historical performance data, MDOT currently experiences a 33 to 34-year service life on asphalt and concrete pavements, before a major rehabilitation or reconstruction is needed. During this time span an average of three CPM treatments are conducted on hot mix asphalt roads and four CPM treatments on concrete roads.

While there is certainly knowledge to be gained by advancing new technologies, investing millions of additional dollars per lane mile on new paving techniques is not likely to significantly reduce or eliminate the need for preventive maintenance throughout the life cycle of the road.

In the 2016 “Roads InnovationTask Force Report” presented to the Michigan Legislature by MDOT, the Department summarized that “achieving the existing goal by implementing current design standards and practices has the lowest initial costs.”

With 122,000 center line miles demanding attention throughout the state, many of these  multilane highways, we cannot afford to allow the larger system to deteriorate while costly reconstruction is made to only a few miles per year.

To learn more about preventive maintenance and treatments used to extend pavement life, review MRPA’s response to MDOT and the Michigan Legislature – Pavement Preservation, the Key to Achieving a 50-year Lifecycle.