The Rev. David Medow estimates as many as 10,000 cars make their way to St. Mary Immaculate Parish every weekend, ferrying church-goers to one of 11 masses held on Saturday and Sunday.

Traffic volume is so great, in fact, that the church pays the Plainfield Police Department to help direct vehicles in to and out of the parish's parking lot at 15629 S. Route 59, Medow said.

So two years ago, when church officials learned the state was going to widen Route 59 to four lanes through south Plainfield, they knew their chance to get a traffic signal had arrived, he said.

"We approached (the Illinois Department of Transportation) about it in 2008, and they said, no, that wouldn't be possible," Medow said. "I knew we couldn't accept that answer."  

The church hired the SEC Group of New Lenox to do a traffic study and enlisted the assistance of village officials, state Rep. Tom Cross (R-Plainfield) and Will County Board member Lee Ann Goodson, who's not only a St. Mary parishioner but an aide to Cross. When they presented the results of the study, which included a traffic count, IDOT saw the light, so to speak, he said.

"They said, 'They need a traffic signal,'" Medow said, amused by the turn of events.

There is one proviso, however: St. Mary's has to foot the bill for the new light and will need to build a right-turn lane, he said. The total price tag, which also includes the cost of a new church sign, is expected to be about $500,000, he said.

"Nobody likes to pay that much, but the state doesn't have the money," Medow said. "If having to pay for it ourselves meant that was the only way it was reasonably going to happen (we had to do it). And if it saves one life (that might be endangered otherwise), it's worth every penny."

Because the state cannot strike a deal directly with the church, the next step will be for the village to sign a contract with IDOT to have the work done, Plainfield Director of Public Works Allen Persons said. The village will essentially serve as the middleman, he said.

"I think they have done a great job getting this accomplished," Persons said.

The contract between the state and the village will be approved by the Plainfield Village Board sometime after the first of the year, Persons said. The signals won't be erected until late spring at the soonest, Medow said.

It's deceiving just how large St. Mary's Parish is, said Medow, who's been with the church since 1998 and pastor since 2005. It's the largest Catholic church in Illinois, with 27,000 registered parishioners. Given the number of programs held there all day long, coupled with the fact that the parish also has an elementary school, the volume of people coming and going can be surprising, he said.

Even the traffic consultant underestimated just how busy things would get, Medow said. On the first day of the traffic count, the woman keeping track of vehicles was overwhelmed and by mid-day had asked her husband to come help, he said.

"She called me and said, 'The traffic count is so high. Will it be that bad on the weekend?" Medow said. "I told her, 'No, it will be worse.'"