VI. TRANSPORTATION / CIRCULATION

1. There are no long-term traffic impacts (i.e., increase in traffic or congestion) for Corona Road or North McDowell Boulevard. Only several operations and maintenance trips are expected per month, as the proposed substation would be controlled remotely. Traffic would increase only during project construction. An average of up to 12 workers (over duration of construction), and fewer than ten trips of slowing-moving construction vehicles per day would arrive and leave the site.

   During project construction, road and lane closure would be necessary temporarily along Corona Road and North McDowell Boulevard. The closure of both roads for the stringing of the 115 kV lines would require about a maximum of one hour and PG&E has proposed to close roads only during non-commute hours. The installation of the new pole on the northeast corner of Corona and North McDowell Boulevard may require lane closure; reduction in traffic lanes would be limited to one day during construction of the project. Such temporary closures and reduction in lanes would be scheduled during times of reduced traffic flows and coordinated with the City of Petaluma (PG&E, 1997).

   The existing level of service (LOS) for Corona Road and North McDowell Boulevard is described as LOS B and LOS C, respectively (PG&E, 1997). LOS B is described in the City of Petaluma General Plan as "Stable flow. Some slight reduction in maneuverability and speed. Slight delay." LOS C is described as "Stable flow or operation with higher volumes. More restrictions on maneuverability and speed." PG&E proposes that temporary closures and reduction in lanes would be scheduled during times of reduced traffic flows and coordinated with the City of Petaluma. A detailed traffic plan, subject to the approval of the City of Petaluma, would be developed by the construction crew during the construction phase.

   The presence of slower moving vehicles compounded with lane and road closures during the construction period could render impacts to traffic flow potentially significant. However, because construction activities are temporary (four months) and because PG&E has proposed that road and lane closures would be limited to short durations during periods of off-peak traffic, this impact is considered less than significant. Additional mitigation is not required.

2. There are no proposed roadway modifications to Corona Road at the entrance of the Service Center or to the adjacent entrance road. No impact related to traffic safety hazards from design features would occur.

   As mentioned in VI.a, construction related vehicle trips would average less than ten trips per day. These slow moving vehicles would transport construction materials such as soil, gravel/crushed rock, and concrete. While turning movements of trucks create some hazards, it is unlikely that these trucks would introduce substantial safety hazards. Good sight lines are present in the construction area along Corona Road and North McDowell Boulevard. The impact with respect to hazards is therefore considered less than significant.

3. Beyond new landscaping, the entrance to the Service Center would not be modified, thus no change in emergency access to the substation site would result. Access to the City’s Fire Station (1001 North McDowell Boulevard) would not be affected by the long term operation of the substation or the presence of the power lines. Because of the proximity of the Fire Station, Corona Road is an important access route for fire trucks and emergency response vehicles. During construction activities, temporary lane and road closures would be necessary as discussed in VI.a, above. This could impair ingress and egress to the fire station as well as delay the travel time of emergency response were such to be required at a time coincident with lane closures during construction. Construction activities in roadways would be subject to the standard procedural and safety measures in the Work Area Protection and Traffic Control Manual, which provides guidance for construction work in street right-of-ways. Implementation of these standard construction practices (maintenance of steel trench plates and proper signage) and notification of planned activities to Fire Department officials and the City of Petaluma would be required to ensure that access for emergency traffic is maintained. The potentially significant impacts to emergency access would be reduced to a less-than-significant level.

   The following measure, along with those proposed by PG&E as part of the project in its application, and in the Work Area Protection and Traffic Control Manual would reduce the potential impact of inadequate emergency access to a less-than-significant level.