Tetra Tech is leading a multi-consultant team for the Allston Multimodal Project to improve Interstate 90 connections, increase safety and accessibility for all travel modes, and enable future development.

Our engineers and environmental scientists are helping the Massachusetts Department of Transportation (MassDOT) with this more-than-$1.5 billion highway interchange project to replace an aging viaduct, realign a major regional connection into Boston, and improve livability and connectivity for residents. We have developed an extensive series of complex infrastructure alternatives, performed comprehensive traffic engineering analysis, prepared the accelerated delivery of National Environmental Policy Act and Massachusetts Environmental Policy Act filings, and provided highway and bridge design and hazardous materials assessment services.

Tetra Tech has supported MassDOT through an unprecedented public outreach and participation process with numerous stakeholders and regulators, and has advanced the project in close coordination with MassDOT and Federal Highway Administration leadership.

Our team worked closely with the Central Transportation Planning Staff to develop a comprehensive traffic model to test various interstate highway, ramp, and local street network alternatives. The extensive traffic analysis considered multiple options to realign the existing highway and interchange ramps and helped set the foundation for the project alternatives included in the accelerated delivery of state and federal environmental review filings.