As state transportation officials prepare to replace the elevated section of the Massachusetts Turnpike that runs between Boston University and the Charles River, they are facing an age-old problem – whether to strive for the absolute best approach or whether to pursue what’s best under the circumstances.

Both Di Mambro and Berkowitz recently submitted comments to the state on the current plan for the Turnpike project, which calls for replacing the elevated portion of the highway, which is 60 years old and falling down, and addressing a host of transportation issues in the Allston I-90 area.

The state’s current plan is to put the Turnpike, two railroad lines, and a pedestrian and bike path at ground level and run Soldiers Field Road above. After years of insisting the Charles River should not be touched during construction, state officials have also concluded that they need to temporarily run Soldiers Field Road and the bike and pedestrian path out over the Charles River during the estimated 10-year construction period.

The potential impact on commuters of this project could be immense. During construction, the Turnpike will have six lanes instead of eight and the Worcester commuter rail line may be periodically reduced to one track in the area.