The Graton Resort & Casino, which is set to open outside Rohnert Park on Nov. 5, could mean an increase of 40,800 vehicle trips a day on Highway 101, a report prepared for the county says, but some officials said the figure could be much lower.
"If that is the case, it would be a backup from Rohnert Park Expressway to Petaluma," CHP Officer Jon Sloat said, referring to the upper-end projections.
The Board of Supervisors is to review today the report by consultant Robert Marcucci, a former San Rafael Fire Chief, part of a presentation that focuses on preparations for the casino's opening weeks.
In 2012, according to Caltrans data, the combined number of north- and southbound vehicle trips on Highway 101 south of Wilfred Avenue — which will be the primary freeway exit for the casino— averaged 97,000 a day.
Officials who have been planning for the opening for two months say they are prepared for the worst eventualities. But they generally downplayed that possibility, while also acknowledging that bad traffic backups are a worry.
"It's a high number," Rohnert Park Public Safety Director Brian Masterson said of Marcucci's projections. Based on conversations with casino management, numbers more along the lines of 8,000 to 10,000 visitors a day are expected, Masterson said.
Also, traffic to the casino will be spread over the 24 hours a day it is open, ameliorating its impact.
"It trickles in, versus one huge rush," Masterson said. "That is an advantage."
The casino's environmental report anticipated 14,274 additional vehicle trips a day because of the project. Casino opponents have consistently said the number would be 40,000.
"We have plans going from if we don't see much of any impact to what do we do if there's complete gridlock," Darrin Jenkins, Rohnert Park's assistant city manager, said of the city's preparations for the casino's opening weeks.