Halfway through the fiscal year, the city of Tucson has spent about $1.5 million of the $20 million voters authorized for fixing up the roads this year.

The spending so far has been on street surface treatments to keep good roads in top quality shape. At the turn of the calendar year, the city will begin spending more money on more intensive road repair, focusing on roads in worse condition, said Daryl Cole, Tucson's Transportation Department director.

One year ago, city voters approved a $100 million road bond. The money was to be spent during five years, at a pace of $20 million a year. The funding comes from an increase in property taxes for Tucson residents.

The project will pick up in the beginning of next year.

"Our primary paving season is warm weather. Usually the first six months of the year we’ll do the majority of the work," Cole said.

The surface treatments, such as what was done at North Craycroft Road near East Grant Road, on West Mission Road near South Drexel Avenue, or East Broadway Boulevard near Park Place, are generally putting a thin layer of protective asphalt over a street that hasn't deteriorated very much, Cole explained.

“The idea is to not let water penetrate into the cracks. As much as you can prevent that from happening is how you preserve your pavements,” he said.

Water in cracks can cause potholes, and a road with potholes costs a lot more to bring into good condition than one with minor cracking, Cole added.

"It’s similar to if you were putting a roof coating on your roof...the idea is the same thing with pavement," Cole explained. "Anytime I can seal any of the moisture out of the pavement then I prolong the lifespan of the pavement."

That's different than the work it takes to repair a road in worse shape, Cole said.

In that case, he said, "you’re actually going out and removing the top level, the surface of it, usually two inches in depth," and then repaving that layer.

Overall, the program is designed to fix up about 130 miles of major roadways, and a little more than 100 miles of neighborhood streets by mid-2018.

The major roads were identified in the ballot measure approved by voters in 2012. The neighborhood streets were not specified.

The city is working with a city Bond Oversight Commission to serve as a public voice and a watchdog for the spending.

The commission also has a financial role to ensure the spending is done as promised to voters, said Steve Pageau, the commission chairman and a former deputy director for the Tucson Department of Transportation.

The commission is also responsible for selecting which neighborhood streets get which types of repairs, he said.

But the committee members' communication responsibilities go beyond that.

"We also want to have that input into the process that allows (transportation) staff to understand how people who work and live in this community feel about the roadways," Pageau said. The committee wants to focus on " opening up a dialogue."

The commission will propose the first round of neighborhood repairs to the city at an upcoming meeting, he said.