Mayors view underfunded infrastructure as the “most pressing problem” they face, says a new survey by the U.S. Conference of Mayors and Boston University’s Initiative on Cities.

The 2015 Menino Survey of Mayors, released on Jan. 20, says that nearly half of the mayors who responded to the survey say that infrastructure is their biggest challenge over the next five years or more—for issues that are primarily state or federal responsibilities.

That high percentage represents “a striking level of accord for an open-ended question,” says the report. No other topic received more than 20% of the mayors’ responses. “Nearly all of those who referenced infrastructure focused on a lack of funding for upkeep and improvements,” it adds.

Roads are mayors’ top public-works priorities—if they have significant new funding— with about 66%, followed by transit and water-wastewater-stormwater, each at slightly more than 40%, according to the report, which was released at the start of the conference’s annual winter meeting in Washington, D.C.\

Asked what sort of large infrastructure project they would chose if they had an “unrestricted grant” to pay for it, transit led the way, with 22%, followed by roads, at 20%, and water infrastructure, with 18%.

Last month, the mayors’ conference praised the passage of the five-year, $305-billion FAST Act, which reauthorized highway and transit programs. The organization noted the measure’s transit and rail funding and “funding flexibility for local governments.”

The report is a joint venture of the mayors’ conference and Boston University’s Initiative on Cities. Banking giant Citi provided financial support.

The survey is named for the late Thomas M. Menino, Boston’s mayor from 1993 to 2013. Menino, who died in 2014, helped found Boston University’s Initiative on Cities.