Motorists said they welcome the improvements.
"It's amazing how congested it gets and how nerve-racking (it is)," driver Robert Shepard said.
Drivers said they're willing to pay for a little smooth sailing, even in the current tough economic times.
"I almost hate to admit it, but, yeah," Scott Hadley said. "I should look at and say, 'Oh, it's not good for my pocketbook, but often times I'll use 161, the toll road, because I know it's faster."
"Sometimes it's easier just to pay a little bit for convenience," Shepard said. "It's worth it."
Construction on the $4 billion project could begin as soon as 2010.
The improvements are scheduled to be finished by 2015.