@
Vanasse Hangen Brustlin, Inc,
The level of service designation is reported differently for signalized and
unsignalized intersections. For signalized intersections, the analysis considers the
operation of all traffic entering the intersection and the level of service designation is
for the overall conditions at the intersection. Unsignalized intersection analyses
assume that through traffic on the main line is not affected by traffic on the side
streets. Thus, LOS designations are for the turning movements at the intersections
and not for the overall intersection.
Figure 10 summarizes the results of the level of service analyses for the study area
intersections, which are also documented by volume-to-capacity (v/c) ratio and
average delay in Tables 1 and 2. It is noted that the intersections of Central
Street/Ledge Street at Pine Street and Central Street at Palm Street are currently
unsignalized intersections. As part of the Broad Street Parkway construction, the
intersections will be placed under traffic signal control. Traffic operational analyses
were completed for the baseline (with Broad Street Parkway) weekday morning and
weekday evening peak hours.
2.3.3.1 Signalized Intersections
All study area signalized intersections are part of a signal system with time-based
coordination plans. The timing used for the signalized intersection analysis comes
from the Nashua Citywide Traffic Signals at Various Locations Project (2012) for the
majority of the signals. The Central Street intersections with Pine Street and Palm
Street are expected to be integrated into the signal system as part of the Broad Street
Parkway construction project (plans are currently under development) and therefore
intersection timings have been assumed that complement the system timings at
adjacent signalized intersections.
The results of the traffic operational capacity analyses reveal that of the eleven
signalized intersections, seven operate at good levels of service (LOS C or better)
during both peak periods. The signalized intersections expected to operate at LOS D
during one or more peak periods include East Hollis Street at Spring Street /Medical
Center Drive, East Hollis Street at Spruce Street/Harbor Avenue, Main Street at
East/West Hollis Street, and West Hollis Street at Palm Street. Only East Hollis
Street at Spruce Street/Harbor Avenue operates at LOS D under both peak hour
periods. None of the study area signalized intersections are forecast to operate at
poor levels of service (LOS E or F) under the baseline condition with construction of the
Broad Street Parkway.
2.3.3.2 Signalized Intersections (Pre-Broad Street Parkway)
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Additionally, note that previous’ traffic operational analyses of the pre-Broad Street
Parkway condition show poor levels of service (D or worse) along Main Street at
several of the study area’s signalized intersections during one or more of the peak
hour conditions. These Main Street intersections include the following:
v
2
Traffic Operational Analyses in support of the "Broad Street Parkway Final Environmental Impact Statement”, January 2010,
and “Engineering Study” for Nashua #14432, X-A000(372) CMAQ Citywide Traffic Signals at Various Locations, March 13, 2012,
Existing Conditions
