The report – the Maryland chapter’s first -- was released at a news conference Tuesday morning in Annapolis, where lawmakers are expected to debate proposals this year to provide an infusion of new revenue for transportation. The most likely source under discussion is an increase in the state's 23.5-cent-a-gallon gas tax.

The report gave the state's roads and transit systems grades of C-minus, while its efforts to maintain its bridges won a B-minus along with compliments on Maryland's progress in reducing the number of structurally deficient spans. Maryland dams received a C. On the water utility side, beside the low statewide mark for storm water runoff systems, the society gave the Baltimore region a C-minus for drinking water and a C for waste water -- identifying the deteriorating pipeline infrastructure under Baltimore's streets as a critical problem.

Sen. Rob Garagiola, a Montgomery County Democrat who has emerged as a leading advocate of raising new transportation revenue and protecting the existing fund from budget raids, pointed to the roads and transit scores as he warned that the state can't afford to delay a stepped-up infrastructure program for much longer.

Without new investment, he said, “these two C-minus marks are going to slip from just passing to Ds or Fs.”

The report said Maryland can expect continued increases in demand for transit services, which have already posted a 22 percent increase in riders since 2005. But it said the current level of investment is not enough to meet that projected growth and that ““potential budget shortfalls are looming.” The study noted that Maryland has not yet determined how it would fund its share of three proposed expansion projects – the Red Line in Baltimore and the Purple Line and Corridor Cities Transitway in suburban Washington.

Maryland’s highway network is increasingly showing its age, according to the report, with 84 percent of its roadways at least 30 years old. The study gave the State Highway Administration credit for steady improvements in ride quality, largely as a result of road-paving projects financed by federal stimulus dollars. But the engineers said the state is not keeping up with demand for additional capacity, thus adding to congestion.

While the report generally praised Maryland’s road surfaces, engineers said problems lurk beneath the smooth top layer. Kaul said many highways are overdue for a “full depth” rehabilitation – in which the roads are rebuilt down to the subsurface layers.

Maryland’s bridges are in better shape than those in most other states, the report said. The study said only 7  percent of Maryland bridges are structurally deficient, compared with 12.1 percent nationwide, giving the SHA and local jurisdictions credit for a concentrated effort over  the past decade  to repair deteriorating spans.

The  state received its lowest grade – a D  -- for its storm water system. The report pointed to an aging infrastructure and the lack of a reliable funding source for projects needed to control runoff and prevent pollution.

While Baltimore received only a C-minus for drinking water, report contributor Tom Spehe said the problem was not water  purity but the aging infrastructure below the surface. Spehe said many of the pipes were built 60-80 years ago using “very old” cast iron technology that is prone to leaks.

Dell. Jon Cardin, a Baltimore County Democrat who took part in the news conference, said he is “very open” to considering a gas tax increase if he can be sure the measure would go to fund transportation.

“My  constituency is much more open to  a gas tax if it is dedicated to transportation infrastructure issues,”  he said.

But Del.  Susan L. M. Aumann, a Baltimore County Republican, thought there would be little support in the  minority for such a measure without an ironclad assurance  the revenue would not be tapped for the general fund – as some  legislative leaders have suggested.

“Until that point,  everything is fungible, everything is liquid mercury  and it’ll flow  to the lowest point,” she said.