In the early 1960s, according to Wikipedia, Route 25 was initially designed by the MassDPW to connect to the Sagamore Bridge.
But canal bridge traffic studies showed that the Bourne Bridge had more available capacity, so Route 25 would connect to the Bourne bridge.
Then construction was hampered by environmental issues, so today Route 25 curves eastward towards Route 3, approaching it within about 2.5 miles.
So we could link the Sagamore Bridge directly to Route 25 via a relatively short connector with appropriate overpasses and ramps.
This new shortcut would alleviate traffic going to the Belmont Circle from Route 25 and from the Scenic Highway. Traffic to the Bourne Rotary would be reduced as the Bourne Bridge traffic is reduced and Route 6A traffic is reduced. All these traffic reductions would result as the preferred connection to Interstates 195 and 495 would be via the new Route 25 connector.
Congress has approved funding the design of upgraded or new canal bridges, as the current bridges are 84 years old. The new designs will inevitably increase the traffic capacity of the Sagamore Bridge. It is anticipated the new bridge designs will be selected this year. Therefore the initial design choice to terminate Route 25 at the Sagamore bridge could now be justified.
An attractive bridge design option could be to add an adjacent parallel bridge to the Sagamore Bridge, so there would be separate southbound and northbound bridges for a total of eight lanes, doubling the current bridge capacity. To integrate the highway system changes, Route 3 would be widened to six lanes between the bridge and the Route 25 connector. In the meantime, traffic management measures, manual or automated, could increase the bridge capacity during periods of high traffic.
The first goal should be the construction of the new Route 25 connector to route Cape traffic to and from routes 195 and 495, away from the Belmont Circle and the Bourne Rotary. This would have an immediate benefit and be done in one to two years.
The canal bridges are crucial to the Cape Evacuation Route, so terminating Route 25 at both bridges would be extremely important. Considering the potential for traffic growth, planning additional Bourne Bridge capacity would be prudent .
Harbor Hill Drive