Bikes on the McGrath Highway? The stateâs preparing to redesign the urban artery By Adam Vaccaro Globe Staff,Updated April 23, 2021, 9:30 a.m. Email to a Friend Soon, McGrath Highway will be cut down to four lanes to make way for bike lanes.Erin Clark/Globe Staff By American standards, at least, the streets of Somerville and Cambridge are a cyclistâs paradise, with green paint, flex posts, and off-street paths lining many key thoroughfares. But then, tearing through the citiesâ eastern edges, stands the six-lane McGrath Highway, much of it elevated on a hefty overpass to carry a heavy load of commuter traffic along Route 28.