Dakota County’s road network will need an estimated $1 billion in fixes and upgrades by 2030 to meet the needs of its growing population, county officials say.

In preparation for the legislative session — which began this week, and promises to bring discussions about transportation needs across the state — Dakota County leaders and staff have been appealing to state and regional leaders for help.

Of the county’s approximately 600 miles of highways and roads, about a third are more than 45 years old. And there aren’t many high-volume routes for traveling east and west, because major corridors were built to connect the county to the Twin Cities, rather than to connect local cities to each other.

At a meeting with Dakota County’s legislators last month, Commissioner Kathleen Gaylord outlined the need for a transportation package to meet the county’s needs. “This is an issue that will not go away,” she said.

Dakota County relies heavily on highways both for cars and mass transit. It is home to the state’s first bus rapid transit line and is slated to get another in 2019.

Metropolitan Council population estimates show that by 2030, Dakota County’s population will be nearly 20 percent larger than it was in 2010. Based on the transportation demand that will follow, county officials are estimating about $500 million in unmet costs for county road projects and up to about $600 million for the county’s state highways.

“At this point, given current revenue streams, we wouldn’t be able to do those projects,” said County Engineer Mark Krebsbach.

Dakota County, like its suburban counterparts, has been vocal for years about a perceived shortchange in transportation funds compared with Hennepin and Ramsey counties. Last month, leaders from four suburban counties released a set of ideas for how to restructure the Met Council by doing away with gubernatorial appointments to the council.

But that challenge to the regional planning agency, which serves as a conduit for state and federal transportation dollars, could complicate the county’s efforts to fund local projects.

At the county meeting with legislators last month, state Sen. Katie Sieben, DFL-Newport, urged caution when it comes to pushing against the Met Council. She suggested suburban leaders propose future changes to avoid damaging relationships this legislative session.

But suburban officials are still planning to lobby for Met Council governance changes — as well as transportation funds — this session, said Commissioner Chris Gerlach.

“We, the county, we’re looking at these issues as separate items,” he said. “Beyond that, how those get done, that’s going to be up to the Legislature.”