RT and Caltrans are ramping up the rhetoric over who should pay for additional mass transit service during the Fix 50 project.

RT Head Mike Wiley says Caltrans isn't willing to shoulder their burden of costs.  

"It's fully Caltrans responsibility to offset the cost, and they're unwilling to do that. They've basically offered up maybe a third at most, and that's just unacceptable," Wiley said. 

Wiley says the additional service on bus and light rail lines will cost about $600,000. 

Caltrans Spokeswoman Deanna Shoopman says their figures stem from the 2008 closure and construction on I-5 through downtown.  

"The approved allocation for Sacramento Regional Transit would be $197,000, so that's actually $7,000 more than they received in 2008," Shoopman said. 

Shoopman says Fix50 will not see the closure of more than two lanes at a time and its impact on the region should be much less than the I-5 project six years ago.