"I want to finish what we have begun. I think we've created that expectation," Harper said in an interview, adding those projects are increasingly needed to reduce congestion.
During a meeting of the Legislature's Transportation Interim Committee on Wednesday, Harper asked Utah Department of Transportation Executive Director Carlos Braceras if all those projects likely would be funded by 2024 without such bonding.
"Probably not," Braceras said, adding they are in longer-range plans and are important.
But Braceras said the ability of the state to fund them in coming years will increase as older bonds are paid off. For example, he said the Utah Transportation Commission just finished planning how to spend about $800 million projected to be available in 2018, and "almost half of the revenue was used to pay debt."
As bonds are paid off, instead of spending $400 million a year on construction the state could increase it to $700 million or more, Braceras said.
But Harper said, "If we want these things done, we're probably going to need to issue one more large bond because we've got a lot of large unfinished projects. I think it's time to finish those."
Harper said in an interview that the state hit 85 percent of its bonding limit in recent years amid such projects as the $2 billion rebuilding of I-15 in Utah County. The bonding he envisions could probably keep the state at 60 percent of that limit or so because of other bonds being paid off.
He said he may run legislation for the bonding next year "or 2016 at the latest," and puts the amount at "about $1 billion."
"Everybody knows it has to be done. But putting out another bond is the question," Harper said.
That comes as other big projects and possible bonding are being envisioned. For example, UDOT has began an environmental impact statement on a $2 billion railway to connect the Uinta Basin and its oil fields with national rail lines near Price.
Sen. Kevin Van Tassell, R-Vernal, Senate chairman of the Transportation Interim Committee, said Wednesday if that project is shown to be feasible, it likely would be financed with "a public-private partnership" and bonding.