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5.2.3 Build Options
A traffic-operations analysis, similar to the analysis of existing conditions, was
conducted for the future 2035 DHVs. The analyses were conducted for each Build
option considered for each Strategy.
5.2.3.1 Strategy 1 – Direct Access to US Route 1
Transportation Operations
As described in Chapter 4, Strategy 1 considers three interchange options to improve
direct access to and from US Route 1 and the NASB: Option 1 is the trumpet/loop
interchange; Option 2 is the flyover interchange; and Option 3 is the split-diamond
interchange.
The results of the operational analyses show that each ramp movement at US Route 1
(i.e., merge, diverge, and weave movements) for Options 1 and 2 operate at LOS D or
better. The southbound on-ramp merge movement for both options shows an LOS D
operation with all other ramp movements operating at LOS C or better.
All ramp movements for Option 3 operate at LOS C or better. Additionally, the four
signalized intersections located on the two connector roadways for Option 3 operate
at LOS B
or better. The aggressive TDM program results in modest improvement for all
movements with all three options. However, for most intersections and ramp
movements, the LOS is unchanged.
It is important that the US Route 1 southbound off-ramp to the Coastal Connector
interchange is projected to operate at LOS F by 2035. With implementation of an
aggressive TDM program, the operation improves to LOS E. Nevertheless,
consideration should be given – perhaps in a future planning study – to
reconfiguring the interchange so that the Coastal Connector and the segment of US
Route 1 north of the Connector are aligned as the highway mainline and the segment
of US Route 1 southwest of the Connector being subordinate. Incidentally, this type
of reconfiguration is consistent with the idea of encouraging regional through traffic
to use the Coastal Connector in Topsham rather than Pleasant Street in Brunswick.
The idea of directing regional through traffic to the Coastal Connector was suggested
by many people throughout the public input process.
All three options result in reduced traffic volume demands along Bath Road and
Gurnet Road, which improves traffic operations. The intersection at Bath Road and
Merrymeeting Plaza is projected to improve from LOS E under the No Action
condition to LOS C for each of the three options - with and without the
implementation of TDM. Similarly, the intersection at Bath Road and US Route
Conclusions 147