The Texas Department of Transportation has proposed an extension of the I-45 HOV lanes north to S. Loop 336 in Conroe. The extension is estimated to cost $2 million with construction planned for 2020 unless TxDOT receives additional funding for the project.

"[The lane extension] will provide a way for transit and HOV traffic to have their own lane and help reduce congestion," TxDOT spokeswoman Raquelle Lewis said.

The project has been placed near the top of Houston-Galveston Area Council's Transportation Improvement Plan, a list that includes more than $400 million worth of transportation projects that are prioritized to receive federal funding.

"It's such a small amount of money for something which affects so many people," said Alan Clark, Metropolitan Planning Organization director for H-GAC's transportation department.

Clark said funding for projects at the top of the TIP could receive funding as early as 2014, but the timing depends on the readiness of a project. An environmental impact study is underway to evaluate noise and air quality impact, but Clark said the document is "fairly advanced" and could be sent to the Federal Highway Authority soon.

Once the project receives additional funding, construction could begin quickly. Clark did not estimate a timetable on when construction could begin, but he estimated it would take less than a year to complete.

Clark said the extension requires no significant construction. The concrete barriers of the current lane will not be expanded. Instead, the project will include striping, signage and "candlesticks," or visible barriers which will not damage vehicles.

The current HOV lane—which ends just north of FM 1960—also serves as an HOT lane, meaning single-occupant vehicles can use it for a fee. Clark said there has been no discussion yet of this extension being designated as a HOT lane.

"I think it would make sense to open these lanes to see how much demand they have and then see how much need there would be for single-occupancy vehicles," he said.

Also unlike the existing lane, which forces traffic to drive southbound in the morning and northbound in the afternoon, Clark said, the proposed extended HOV lanes would likely allow northbound and southbound traffic all day.

Clark said the improved mobility from this project could benefit all motorists on I-45.

"For those persons who are eligible who use the facility, congestion frequently now backs up in Montgomery County; this is going to make traffic time less and make it more reliable," Clark said. "And if I can't use a carpool, it's nice to know that my neighbor is not occupying the lane next to me and is on a bus."