Tetra Tech completed innovative highway and traffic engineering design services to meet an accelerated design schedule for the Massachusetts Department of Transportation (MassDOT) Acceler-8 design-build project.

Our transportation and traffic engineers completed designs for this fast-track project for six bridge superstructure replacements and two complete bridge replacements on a 3.3-mile section of Interstate 90 in Southborough and Westborough, Massachusetts. To meet the accelerated schedule, we developed two separate highway plan sets and two early release plan sets to enable procurement and construction to proceed on schedule.

Accelerated Bridge Construction methods and weekend traffic crossovers allow for safer and more efficient construction, according to MassDOT.

We developed extensive temporary traffic control plans (TTCP) to maintain traffic on both highways and local roads during the eight weekend work periods. Our team’s innovative approach included temporary median crossovers for the operation of two-way interstate traffic in one directional barrel separated by movable barrier using a transfer machine. These complex TTCPs included coordinating and implementing local detours, real-time traffic management, advance signing, and short-term and long-term traffic management to enable all construction activities to proceed on schedule.

Our scope included work zone pavement drainage design in conformance with Massachusetts Department of Environmental Protection Stormwater Management Standards. We also developed the Stormwater Pollution Prevention Plan pursuant to U.S. Environmental Protection Agency’s National Pollutant Discharge Elimination System General Permit for Discharges from Construction Activities.

Photo courtesy of RDV Systems, Inc