PLEASANT HILL -- More than two years after the Safeway gas station opened at Sunvalley Mall, drawing long lines and tying the parking lot up in knots, more pumps could be in service by the end of the year.

Safeway plans to install four more double-sided gas pumps, raising the total number to 10. The plan also calls for extending the canopy over the pumps by 50 feet and removing 28 parking spaces to make room for up to 20 vehicles to line up for gas.

The Planning Commission approved the use permit for the project last week, and the Architectural Review Commission is scheduled ¿to take a look at the canopy, landscaping, parking and signage on Thursday.

Safeway wants to install the pumps by the end of the year, and the gas station will close for four to five weeks during construction, according to spokeswoman Wendy Gutshall. The four new gas pumps are expected to generate 260 additional daily trips to the gas station.

The grocer also will pay to install a "partial" traffic signal at the left-turn pocket on Contra Costa Boulevard just south of the gas station directly across from the mall parking lot entrance near the Firestone building. Vehicles waiting to turn into the lot will trigger the stop light.

"It's going to allow people to make that left turn into the mall parking lot or a U-turn without bleeding out into Contra Costa Boulevard," said Rod Wui, Pleasant Hill senior civil engineer.

The city also will extend the concrete median at the same location to prevent motorists from making a left turn from the mall parking lot to southbound Contra Costa Boulevard.

There have been long lines at the gas station since it opened in February 2012. Safeway typically has cheaper gas prices than the national oil companies, and customers who participate in the company's rewards program can save even more.

To ease congestion in the parking lot before the September 2013 opening of Nordstrom Rack, which sits directly across the parking lot from the gas station, Safeway changed the circulation plan so that vehicles enter the gas station from Contra Costa Boulevard instead of via the original entrance north of the station on Golf Club Road. Currently, the line for gas runs parallel to Contra Costa Boulevard and spills over into a parking lane, blocking some parking spaces. This configuration was put in place while Safeway worked with the city on several studies analyzing the amount of traffic additional gas pumps would add to nearby intersections and to the parking lot.

"The temporary solution of the revised circulation pattern had results we anticipated of freeing up space and creating easier vehicular flow throughout the parking lot," Gutshall wrote in an e-mail.

Even though some parking spaces were frequently blocked, fewer customers have complained about parking lot congestion since the changes were put in place last fall, said Michael Fenley, Sunvalley mall's general manager. Still, he looks forward to the gas station's expansion.

"We know that there's ample parking in that area for both Safeway and Nordstom Rack, and we think the elimination of some parking spaces to improve access to the fueling station is a very positive trade-off and we support it completely," Fenley said.

Lisa P. White covers Concord and Pleasant Hill. Contact her at 925-943-8011. Follow her at Twitter.com/lisa_p_white