AUSTIN, Texas -- It has been three weeks since the Northbound express lane on Mopac opened, and now, the wait for its southbound counterpart is finally over.

As of Saturday at 8 a.m. drivers can take all or part of the 11 mile express lane.

It begins at Parmer Lane and stretches to the 5th Street/Cesar Chavez exit to downtown, with a midway exit and entrance at 2222. 

"We've picked the places that made the most sense to have entry and exit points based on traffic volumes," said Steve Pustelnyk with the Central Texas Regional Mobility Authority.

CTRMA said if the southbound lane is anything like the northbound one, it will be heavily used.

"We've had more than 200,000 trips on it so far," Pustelnyk said. "At rush hour the lane's essentially full, and we've been seeing average toll rates during rush hour for a full length trip in the 4-dollar range."

Quite the gap from the standard 25 to 50 cent fee. Demand for the southbound lane is expected to be high during the weekday morning and afternoon rush hours, and since it's just one lane, drivers shouldn't get used to using it daily.

"It's not something everbody can use every day, it's really for those days when you're in a hurry and you have to be somewhere, and you have to decide on any given day whether the price is worth it any given day," said Pustelnyk.

But with traffic being notoriously troublesome, people might be willing to pay a pretty penny now that they have the option.

Since the traffic flow changes due to the express lane, be ready to make safe lane changes ahead of the express lane entrance, so you don't have to cut across multiple lanes of traffic.

Slowing down once inside the express lane is prohibited unless there is congestion.