Cabinet members met on Wednesday to discuss the option, which would incur £5m in costs for development work alone.
The figure does not cover expected running and operating costs of the scheme, which council leader Sir Steve Houghton is concerned will be too substantial for the borough to afford.
Sir Steve said: “What we have to say regarding franchising is that in the short and medium term, it is very unlikely to provide solutions.
“This is by no means a ‘quick fix’ scenario.
“This isn’t a move which will fix all existing problems, this is moving from one system to another - so to improve it would have even more cost implications.
“I’m happy to move to the next stage but we need to get a greater financial understanding.
“There will be a cost of some variety at the end of all this, and the trouble is working out how to afford that.”