The I-90 / I-93 Central Artery Project is America's current largest transit and highway design project. This project is comprised of roadway, bridges, tunnels and support buildings and has a construction cost of over $11 billion.

For over five years, Primary Group has been a member of the lead design team for this project, a four firm group which has designed all the architectural elements of this vast effort.

Individual projects include the architectural design of an eight-lane cable stay bridge, ventilation buildings, maintenance buildings, security buildings, toll plazas, highway elements, tunnel finishes and signage.