The data collected from the first 60,000 trips on Boston’s Street Bump app tells us that Boston’s road bumpiness is primarily driven by metal castings that are no longer flush with the road. We want a good fix for this. Our Public Works Department has done extensive analysis of its roadways and what reduces their smoothness for cyclists and drivers. The most problems seem to arise from metal castings that have sunk below or popped above the asphalt around them. These castings – or manhole covers – are usually removable, providing important access to the utilities below ground.

Fixing sunken or raised manhole covers often requires cutting into the road to reset the castings. Cutting into the road not only raises costs but also causes traffic congestion. More importantly, cutting into the road hinders the integrity of the roadway itself, often resulting in potholes and hastening the need for additional investment in complete roadway resurfacing and reconstruction.

Across Boston's 800 miles of roadway, there are over 30,000 castings. While the castings are distributed throughout the city, a significant number tend to be on the older, higher traveled thoroughfares in our neighborhoods and downtown areas. In a preliminary review, the City has already identified at least 1,000 castings in need of repair.

We imagine a solution to this problem that takes one of two approaches. We are interested in new designs for castings that, at a low cost, can better withstand the pressures of heavy traffic and tough winters. Additionally, for those castings that become problematic, we are looking for designs or technologies that can make the road smooth again while minimizing destruction of the surrounding asphalt surface. In both cases cost is an important consideration.