North Bayshore: Trip Caps and Monitoring
As a result of Mountain View’s 2030 General Plan, the North Bayshore Precise Plan (adopted in 2014) was developed to identify specific improvements in land use, ecology, mobility, and infrastructure for the employment-dense area north of Highway 101. To achieve this, the plan includes transportation demand management (TDM) mandates for employers and other tenants in the area, in addition to land use requirements intended to limit vehicle trips, reduce congestion, and encourage shifts away from single-occupancy driving.
The North Bayshore area is described by the plan as an area, “located in the northern end of the City, bordering Shoreline at Mountain View Regional Park to the north, Highway 101 to the south, Palo Alto to the west, and Stevens Creek to the east (Figure 1). The Precise Plan area is geographically distinct due to being separated from the rest of the City of Mountain View by US-101.” The area is noted as a “major high-tech employment center” with the city envisioning the area as a model for “stewarding biological habitat.” Shoreline Boulevard serves as a key corridor for the area, with mixed-use development and pedestrian friendly activity amongst a hotspot of campus-style employment centers.
Figure 1: Existing Street Network of North Bayshore Area
The plan contains myriad interventions for the North Bayshore area, several of which are directly related to TDM. The most direct tactic to manage congestion listed in the plan is a ‘trip cap’ which limits the number of vehicles entering the Precise Plan area at the three gateways (San Antonio Road, Rengstorff Avenue and Shoreline Boulevard): 8,290 trips in the 3-hour A.M. peak period and 8,030 trips in the 3-hour P.M. peak period. If the area exceeds the trip caps for two consecutive data reporting periods, the City will not grant any new building permits for net new square footage in the Precise Plan area until the number of peak hour vehicle trips is reduced below the trip cap.
Another goal envisioned as part of the plan is a target for single occupancy vehicle (SOV) trips to comprise no more than 45% of the area’s mode share. In 2013, the Shoreline Regional Community Transportation Study showed that 61% of trips made in the area are SOV trips. To accomplish this reduction, the City of Mountain View will require employers and property owners to put TDM strategies in place to meet these targets at a small scale with coordination across the entirety of the district.
The plan includes a possibility for congestion pricing within the district to be implemented by the city. Congestion pricing would entail a fee for all vehicles, or certain categories of vehicles, to enter the district during peak hours. To implement such a strategy would require additional consideration, but may be a helpful tool for attaining the plan’s objectives should the other methods need additional support.
As part of the Precise Plan’s implementation, the City of Mountain View has commissioned trip monitoring reports from third-party consultants at least twice a year. Reporting from Spring 2018 show an overall, inbound peak hour trip count that meets the demands of the plan. However, this inbound traffic is imbalanced, with the gateway at Shoreline Boulevard exceeding its intended capacity. The gateways at San Antonio Road and Rengstorff are under their capacities. The report notes that current employers, property owners, and tenants will need to reduce trips to accommodate future development into the trip cap.
In terms of mode share, SOVs comprised 51% of all vehicle trips the morning peak and 45% of the evening peak in Spring 2018. The morning peak currently exceeds the goal for proportion of SOVs stated in the plan, but still shows improvement from the measurements gathered in the Shoreline Regional Community Transportation Study.
Monitoring and managing the trip cap is a complex process that often needs revaluation to ensure effectiveness. In 2017, the City of Mountain View modified the counting methodology to include trips in both directions in anticipation of new residential developments in the North Bayshore area. This change faced criticism from employers in the North Bayshore area because it decreased the trip cap for inbound employees. Jeral Poskey, a representative from Google, noted at the September 2018 City Council meeting that a lower trip cap could result in induced demand. Induced demand could occur if congestion is alleviated to a point where more people are more inclined to drive, which could increase the number of SOVs to the original levels.
City Council has also noted that the trip cap is a mechanism for addressing congestion and SOV rates in the area and should not be used as a tool for impeding new developments.