AUSTIN (KXAN) — Sitting in traffic on North MoPac makes the idea of an express lane a little more appealing.

Recently, the MoPac Improvement Project has been airing advertisements that walk drivers through how the new lanes will work. The ad also explains that the express lanes are not meant for everyday use, rather they are meant for occasions when you can’t afford to be late.

Dee Anne Heath, the project’s director of external affairs, says it’s not about discouraging drivers from using the lanes.

“The purpose of an express is to provide a reliable travel time for drivers and the way that we do that is, that lane has to remain free-flowing,” explains Heath. “This lane is designed for when you absolutely have to pick your child up from day care; you have to get to a work meeting.”

In order to make sure the lane remains consistently free of backup, workers will monitor the lanes in real time at the Traffic Management Center determining how the toll rate needs to be adjusted. Currently, officials are estimating the express lane could cost between $2-$3 per section, for example traveling between Farm to Market 2222 and Parmer Lane. At this time, there is no ceiling on how high toll rates could reach.

“It’s going to vary by people, by what they’re doing in their day, what time of day, what time of year. All of those things are going to factor in to help us understand what value people are placing on their time,” says Heath. “The purpose of this lane is to provide an express route for people that need it when they need it. This a really great way to navigate congestion when you’re dealing with capacity limitations.”

The lanes will be free for buses and emergency vehicles.Behind Schedule

The MoPac toll lanes were originally slated for completion fall of 2015. The project has been delayed numerous times due to a variety of problems ranging from the discovery of a small cave to issues related to weather. In December, the company overseeing the project, CH2M, said the lanes would open in summer 2016—but that has deadline has come and gone.

The project contractors are facing up to $20 million in penalties for not having the project complete on time.