TAMPA — Drivers on the Veterans Expressway will gain an extra lane from Gunn Highway to Hillsborough Avenue starting Saturday.But there’s a catch: Once drivers enter the lane, they won’t be able to leave it — not until a designated exit about six miles later.PREVIOUS COVERAGE: Veterans Expressway to gain higher priced express toll lanes in 2017 (March 4, 2016)There will be no merging, no changing of the mind. If commuters miss the entrance, they won’t be able to jump in later. Plastic poles separate the lane from the rest of traffic.Welcome to the world of express toll lanes and dynamic pricing, Tampa Bay. Miami, Washington D.C., and other cities across the country are familiar with these toll concepts. Now local drivers will be introduced to them.Once the other three-mile stretch of the extra lane from Gunn to Dale Mabry Highway opens in the spring, drivers will have to pay an extra toll — on top of the one they already pay to use the Veterans — if they want to bypass traffic using this new 9-mile express lane. The price of that toll will rise and fall based on demand. The more traffic, the higher the cost to avoid it.But drivers won’t have to pay extra to use the express lane just yet. Florida’s Turnpike Enterprise is choosing a slow rollout. The agency said opening the express lanes for free allows them to ensure the accuracy of the toll equipment and helps drivers get used to where they can enter and exit."At this time, I think the department is just focused on opening the lanes, letting drivers get used to the lanes, and get used to the flow and function of them," spokeswoman Kelda Senior said.PREVIOUS COVERAGE: New 2024 Howard Frankland plan: 8-lane bridge with bike path (Oct. 2, 2017)The exact date when the new express toll lanes come online is unknown. So is how much it will cost drivers to use them.Turnpike officials said last year that it would cost an extra 25 cents to use the express lane. This week the agency said the price will be "market driven" but did not offer specifics, nor say how that cost will be calculated or if there will be a cap.For an example of what express lanes can cost, look to Miami. Tolls on the 7-mile stretch of Interstate 95 top out at $10.50 one way. Officials have considered raising the limit to $14, or $2 a mile.It already costs hundreds a year to drive the Veterans. It costs $1.06 to drive one-way from Gunn to State Road 60. Commuters who travel twice a day, five days a week, pay up to $550 a year with a transponder. If they opt for the more expensive toll-by-plate option, that cost jumps to about $715 a year.Drivers will know the price of the express lane before they enter it. It will be displayed on overhead signs, helping them decide whether or not it’s worth paying more to avoid traffic. Once drivers enter the lane, they’ll be charged that rate, an increase after that won’t affect them.They’ll also need a SunPass or other transponder to use the express lanes. Toll-by-plate option will not be accepted in express lanes.Lindsay Lewis, who drives the Veterans every week day from Hernando County to W Waters Avenue, said she already spends an average of $120 a month on tolls. That’s more than she pays for gas each month for her hybrid.She tries to alter her route occasionally to save money, but paying the tolls helps her get to work on time. Lewis, 30, said she wouldn’t even consider paying an extra toll on top of that."Some people will pay it if the traffic’s bad, but I think it’s a waste," Lewis said. "It would’ve been more proactive to just build another lane to help with the traffic flow."Darren Ochab, 31, said he’s looking forward to the express lanes. He won’t use them — they start at Gunn and he gets on at Waters — but he hopes it will eliminate all the extra merging that slows his commute. Once drivers get in the express lane, they’ll stay on them for at least six miles."The traffic merging onto the Veterans combined with all the drivers already on it changing lanes at the last minute creates a lot of problems," he said. "The only way to alleviate congestion without adding more lanes is to actually get people in the lanes they need to be in a lot sooner.TAMPA BAY TIMES: TAMPA BAY EXPRESS COVERAGE Goodbye Tampa Bay Express, hello Tampa Bay Next; but toll lanes aren’t going anywhere Take 2: Some fear Tampa Bay Next transportation plan is TBX reduxTBX Next: How the $6 billion plan has changed in the last yearExpress toll lanes and fluctuating prices is something bay area commuters will have to get used to. The Florida Department of Transportation will roll out miles of express toll lanes throughout the region over the next few years as part of its Tampa Bay Next project, the new iteration of the old Tampa Bay Express plan to add tolls to currently free interstates.Those new toll lanes will start in the Gateway area, stretching across the Howard Frankland Bridge and include parts of Interstates 275, 75 and 4.The safety of the express toll lanes on Miami’s I-95 has been criticized because of "lane diving" — drivers crashing through the plastic dividers and dangerously veering in and out of the express lane.A nearly 4-mile stretch of I-95’s express lane was named the most deadly road in the state by a study conducted by Stein Law Group and marketing firm, 1POINT21. The data showed the road had a fatality rate of 7.01 per mile.Law enforcement and some South Florida lawmakers have criticized express lanes in recent years. Records show troopers were called to more than 12,000 crashes in the express lanes in Miami-Dade over a three-year period.The Florida Highway Patrol has said the poles do nothing to stop lane diving. However, express lane crashes have dropped by about a third since the state doubled the number of highway poles separating the lanes last year.Information from the Miami Herald was used in this report. Contact Caitlin Johnston at [email protected] or (727) 893-8779. Follow @cljohnst.