Opportunities at the Intersection of Route 6 Hydroplaning and Stormwater

Certain segments of Route 6 are prone to unsafe hydroplaning conditions. A new report by Cape Cod Commission staff identifies the most problematic areas and offers strategies to increase safety and improve water quality through better stormwater management practices.

Among the study’s finding are:

• The predominant wet weather safety concerns occur  between exits 5 and 7, with 52% of the study’s total crashes
• The segments between exit 9 and the Orleans Rotary have widespread drainage issues.
• The most severe puddle covering both driving lanes between exits 10 and 11 westbound
• The 9.6 miles between exits 6 and 9 cross sub-watersheds requiring a 100% reduction in septic nitrogen.

After an initial review of crash data, the study focused on Route 6 between the Sagamore Bridge and Orleans rotary. Staff analyzed 2006 to 2010 MassDOT Registry of Motor Vehicle records for crashes, current stormwater management practices and developed alternatives to address safety and environmental concerns. The sensitivity of the Cape’s drinking water and coastal resources to nutrient and pollutant loading led to recommended stormwater solutions and alternatives that address nutrient attenuation and improve water quality.

Preferred alternatives address the specific needs for each segment and provide suggestions to improve roadway surface and function, stormwater techniques to facilitate rapid removal of roadway runoff and methods to reduce the nitrogen contribution from Route 6 to the Bass River Watershed.

Commission staff assisting in the research, analysis and drafting of the report were Natural Resources Specialist Heather McElroy, Technical Services Planner Steven Tupper, Hydrologist James Sherrard and GIS Analyst Bret Whiteley. The report benefited from the review by Water Resources Program Manager Tom Cambareri.  Special thanks to MassDOT contacts Pam Haznar and George Ayoub for providing relevant historical and current information for Route 6.

The report, entitled “Route 6 Hydroplaning Crash Analysis and Alternatives Development,” is available on the Commission’s website.