How safe are Vermont's bridges?

New information about the safety of Vermont's bridges. An engineering society gave Vermont's bridges a C rating back in 2014 when 30 percent of them were considered deficient. Since then, Vermont lawmakers have been pumping money into VTrans trying to keep the state's bridges safe for drivers.

So how is Vermont doing with meeting its goals? VTrans says for them, it's not about the grade. The agency says its workers and engineers are up against Mother Nature and differing federal guidelines that make it difficult for them to get ahead of other states.

Right now, 5 percent of Vermont's bridges are considered structurally deficient. Structurally deficient bridges have significant deterioration to a major part of the bridge but are not necessarily unsafe.

VTrans says that percentage makes the state 35th in the country. But Chief Engineer Wayne Symonds says states in the Northern Tier are at a disadvantage.

"The ones that are ahead of us are in states like Nevada or Arizona, where they don't have the climate challenges that we have," Symonds said.

He says they have seen an increasing number of freeze-and-thaw cycles.

"Every time it does that, that's something that take a little bit of life out of the concrete or out of our pavement," Symonds said.

The federal government also has different standards than Vermont. The historic covered bridges count as functionally obsolete. They-- along with many other town bridges-- are too narrow and have a lower clearance than more modern bridges.

Time is also working against VTrans. Many of Vermont's bridges were replaced after the 1927 flood. They are all around 80-90 year old and ready to be replaced.

VTrans sorts bridges on a priority list which state lawmakers use to designate funding.

"That's why we've made a tremendous amount of progress. Because if they really get bad, they get to the top of the list," said Sen. Dick Mazza, D-Grand Isle.

"It doesn't make sense to replace them all," Symonds said. "Sometimes a small investment now can save money going into the future."

Back in 2008, VTrans estimated it would need $110 million every year for 20 years to address Vermont's bridge deficiencies. About $100 million is set aside for bridges out of this year's $600 million state transportation budget.

"Things change over the years," Mazza said. "We were able to do much more than we thought we could do with our money."

The state has been able to surpass all of its improvement goals. That's partly because VTrans started using accelerated bridge construction in 2012. Pre-making pieces and assembling them on site is faster and cheaper, allowing VTrans to tackle more bridges, cutting the number of structurally deficient bridges almost in half every five years.

"If that bridge has any indication it's not safe, it's closed," Mazza said.

VTrans officials say they are always looking for ways to extend the life of bridges. Right now, they're looking into the advantages of using fiberglass reinforcement instead of traditional steel and using less permeable concrete. The goal is to get these new bridges to last 100 years.