Hutton Marshall | Contributing Editor

As the redevelopment of Grantville moves closer to becoming a reality, a new state-mandated environmental review predicts problematic traffic increases in the area and suggests road improvements to mitigate congestion.

The overhaul of the community plan for Grantville will transform a largely industrial portion of the neighborhood just east of Mission Valley, and, among other community planning measures, rezone the area to promote construction of dense, mixed-use residential development while making it more accommodating for active transportation such as biking, walking and public transit. The plan is in step with San Diego’s City of Villages concept, which envisions neighborhoods where residents can live, play and work without trekking far from their home.

While the plan ultimately aims to create a Grantville less reliant on the automobile, adding as many as 4,500 residential units to a 280-acre area will inevitably increase traffic.

Much of the redevelopment, especially where getting from one place to another is concerned, hinges around the Grantville trolley station, which is served by the Green Line, connecting eastern San Diego to Downtown. City planners hope to use the trolley station as a focal point in future developments, building mixed-use apartments within walking distance to encourage use.

And while the Grantville trolley station is currently underutilized, the environmental report found that when you factor in the three bus routes running through the area, the percentage of local residents using public transit exceeds city averages. The redevelopment plans also call for renovating all bus stops in the Grantville area to include canopies and improve surrounding pedestrian access.

Things get trickier where traffic is concerned.

Mission Gorge Road/Fairmount Avenue and Friars Road are the main thoroughfares in Grantville, which is bordered by interstates 8 and 15. Currently, about 30,000 drivers pass through the busier portions of Mission Gorge Road each day. Friars Road handles about 40,000 drivers a day on the stretch passing through Grantville.

By 2030, the environmental review predicts Mission Gorge Road traffic will increase by approximately 5,000 drivers. Friars Road will increase by 20,000 daily drivers in some areas, according to the study. Twain and Fairmount avenues would also see sizable increases.

Traffic engineers use a grading system for street congestion called Level of Service (LOS), which ranks traffic congestion on a given road at a given time of day by giving it a grade of A through F. The latter grade equals gridlock.

Currently, there are a few Grantville intersections and street segments that get an F during peak traffic hours in the morning or afternoon. One problem intersection is where Friars Road turns onto the Southbound I-15, for example, or where Mission Gorge Road hits Zion Avenue. Still, F grades are few and far between in the sparsely populated area.

By 2030, however, the number of F-grade street segments and intersections will more than triple. Friars Road from I-15 to Riverdale Street receives an F grade in both morning and afternoon traffic, as does Mission Gorge Road/Fairmount Avenue through virtually its entire stretch of the Grantville redevelopment area. Unless one weaved through side streets, the only way to drive through Grantville during rush hour would be bumper to bumper.

California law requires that environmental reviews provide mitigation strategies for project impacts like traffic increases. The environmental report at hand recommends widening several intersections where congestion is predicted, such as Friars Road and Riverdale Street, and Mission Gorge Road and Zion Avenue. It also recommends widening Friars Road from six to eight lanes where possible, and widening Mission Gorge Road by two lanes where possible, presumably by removing the striped median, restriping the street with thinner lanes or removing street parking.

The public now has until Feb. 2 to submit public comments on the project. The entire draft of the environmental impact report is posted under the City Bulletin of Public Notices at sandiego.gov/city-clerk.

—Contact Hutton Marshall at hutton@sdcnn.com.