SEATTLE -- The city calls the South Lake Union streetcar the future of transportation. But in the present, the streetcars is already being called an additional headache for drivers exiting I-5 at Mercer Street and for other drivers on Westlake.

Three streetcars currently run the route along Mercer Street, and the city hopes to add another to ease traffic. But some already have their concerns.

Driver Tina Favero says she's already not a fan of the I-5 Mercer Street exit.

"Yeah it looks like people are just sitting there doing nothing a lot of the time. It drives me nuts," she said.

Brandon Jacobsen, another driver, agrees.

"I mean, we've already got a pretty congested area as it is this is really the only way to enter the freeway downtown so I don't really see (the point)," he said. "It may help alleviate the traffic eventually, but the traffic that's there now it just seems to add to it."

How does the streetcar affect I-5 traffic? As it approaches an intersection, all of the traffic lights will turn red, bringing all drivers to a stop. That includes all of the traffic coming off of I-5.

When asked whether routing the streetcar through already-congested Mercer Street was a smart move, Project Manager Ethan Melone answered a confident yes.

"Well, that is exactly one of the reasons to provide another option. The mess is (because) everybody (is) in their cars," he said.

Melone said the goal is to get people out of their cars anyway to ease downtown traffic, and he says so far, the city hasn't received any complaints.

But some worry the streetcar will make what's already called the Mercer mess even messier.

"I think it probably will from what I've noticed and what I've seen lately," Favero said.

But Melone insists one has nothing to do with the other.

"No, the streetcar really isn't impacting any general traffic," he said. "The Mercer mess is another separate issue that the city is also working on."

City leaders say they did take note of high-traffic areas when designing the streetcar's route. In some areas, the streetcar does veer out and travel outside of traffic.

As for the Mercer exit problems, the city says it is working on improving the flow of traffic around the corridor.