When gas goes up, bus ridership goes up. And when prices go down, bus ridership declines. At least that’s how the math used to work.

After several months of high gas prices, and no strong dip due anytime soon, more people are becoming permanent consumers of the Nashville Metropolitan Transit Authority and Regional Transit Authority’s offerings.

And as the RTA prepares to launch rapid-transit bus service to and from Clarksville, now is a good time to look at all the options, says Paul Ballard, executive director of the MTA.

“The ridership increases we have seen are sustaining themselves,” Ballard explains. “The cost of operating a car has a lot to do with that; with payments, insurance and gas it costs around $10,000 a year to operate a car. That’s made it a pressing issue.”

The MTA has seen a 15 percent ridership increase over this time period in 2011, but some of the regional bus services that go into surrounding counties are up more than 60 percent. Couple that with the Music City Star, which is up 20 percent, and it’s easy to see why the two authorities are focusing on commuter traffic.

“The further you drive the more options you’re willing to explore,” Ballard says. “You can get on a bus for a reasonable cost, and many employers will pay for that trip. We’re seeing tremendous growth in our park-and-ride services, and when the Clarksville route comes online we think it will immediately be popular.”

The 94X Clarksville Express will launch in June, connecting Nashville to Clarksville by bus for the first time. Each bus holds 55 passengers and offers restrooms, luggage racks and other amenities.

The Clarksville Transit System will provide connections to and from a park-and-ride area, where the buses will pick up and drop off passengers.

The MTA is doing a full-court press to market this and its other options, Ballard says, using traditional and social media. It also is rolling out the first-ever RTA system route map, which will join the existing MTA maps that consumers can pick up around town.

“We are always looking for ways to cross promote both RTA and MTA lines,” Ballard adds. “This new map will show complete routes for the entire region, but will also have the MTA express trips on there. The existing MTA maps only show the metro area, and so that regional information wasn’t out there.

“We’re trying to make sure that people can get transit information about wherever they want to go.”