A multifamily development proposed for a former Massachusetts Department of Transportation maintenance facility is attracting opposition from Medford officials who cite a loss of commercial space and safety issues.

Malden-based Combined Properties proposes to build a 378-unit apartment complex on Mystic Avenue. The site includes a 1.7-acre former MassDOT sign maintenance shop at 300 Mystic Ave. that it acquired from the state in December 2019 for $6 million under Gov. Charlie Baker’s surplus property initiative.

In a comment letter to MassHousing, which oversees the 40B program, Medford Mayor Breanna Lungo-Koehn cited public safety, design and open space shortcomings in the designs.

The property is located in a commercial zone that runs parallel to Interstate 93 and Medford’s commercial-industrial tax base is at an “all-time low” of 10.6 percent,” Lungo-Cohen wrote.

Although the original proposal announced by the Baker administration called for 500 housing units and 53,000 square feet of retail-restaurant space, the currently proposal does not include any ground-floor commercial space and two stories of ground level garage space.

“This project will set the design template for the entire Mystic Avenue corridor, and if the proposed development were replicated along the corridor it would result in an imposing wall of `superblocks’ and a missed opportunity to reinvent the area,’” Lungo-Cohen wrote.

An Algonquin Gas transmission line runs through a portion of the property and access to the site is limited for emergency vehicles, the mayor wrote.

In a comment letter to MassHousing, Andre Leroux, chair of Medford’s community development board, said the 8-story structure should be redesigned with varying heights and include ground-floor retail space facing Mystic Avenue.

The future of the Mystic Avenue corridor became an issue in last year’s mayoral race as then-Councilor Lungo-Cohen accused her opponent, incumbent Stephanie Muccini-Burke, of trying to push through a mixed-use rezoning plan for the area with insufficient public notice. Burke withdrew the amendment in August, and was defeated by Lungo-Cohen in the November election.

Since then, the city has hired Boston-based J.M. Goldson Community Planning + Preservation to compile a housing production plan scheduled for completion this summer.

The proposal is one of three active Chapter 40B projects under review in Medford, totaling over 1,000 housing units.

The Davis Cos. of Boston is seeking to redevelop a 3.4-acre site at 750 Fellsway, a former brick factory later converted into a self-storage facility, as a 289-unit multifamily complex.

And Mill Creek Residential is proposing a 400-unit multifamily complex at 4000 Mystic Valley Parkway, which currently contains a 1-story commercial building.