North Carolina entered the toll-road business quietly Tuesday when the Turnpike Authority began collecting electronic payments from drivers on the Triangle Expressway.

Familiar commuter routes around Research Triangle Park were crowded on the first workday after New Year's, but traffic on the new six-lane expressway was light.

Drivers are just starting to figure out the first 3.7 miles of TriEx, which stretches N.C. 147 south from Interstate 40 through RTP to the 540 Outer Loop. Construction is under way on the rest of the new road, extending 540 through western Wake County. By the end of 2012, drivers will be paying tolls on 18.8 miles of TriEx from RTP to Holly Springs.

The new toll road has exits conveniently close to major RTP destinations, but some commuters are discovering TriEx as a quicker path for bypassing the park altogether.

Chris Endicott, who works in Durham at Duke University, started using TriEx when it opened for toll-free driving in early December. He said he was happy to start paying the toll Tuesday - 50 cents each way on the full length of TriEx, for drivers who have N.C. Quick Pass transponders.

He has cut 15 minutes off his afternoon drive from Durham to his home in Apex.

"It's been a great change to my commute, that's for sure," said Endicott. "It helped out in the evening commute quite a bit. I'm definitely glad to pay the dollar round trip."

Russ Ballard, who works for the U.S. Environmental Protection Agency, is one of many EPA workers who were unhappy when the construction of TriEx forced the closure of a key, free road that once linked I-40 with Alexander Drive.

Ballard complained about delays on his drive to work Tuesday via N.C. 55 and N.C. 54 and said he would have to consider switching to TriEx, which has an off-ramp near the EPA gate on Hopson Road. If he gets a transponder, he would pay 30 cents each way from I-40 to Hopson.

"If the congestion on the alternate routes remains as bad as it was this morning, I guess I'll have to yield to the will of the DOT and shell out 60 cents a day to the N.C. Turnpike Authority," Ballard said by email.

The Triangle Expressway isn't the first U.S. toll project to be built without coin collection booths, but North Carolina - which was the last East Coast state without a toll road - apparently is the first state to begin tolling without ever having collected cash from drivers. More toll bridges and roads are in the works from Charlotte to the coast, and most or all of them will be operated without tollbooths.

No quarters were pitched into baskets Tuesday on TriEx, and no bills changed hands. No drivers stopped or even slowed down for the transaction.

Each vehicle rolled over sensors that counted its axles, to determine which rate would be charged. It passed beneath video cameras that recorded its license number, to identify the owner who would pay the toll. Other sensors identified the cars that had transponders.

When transponder users arrived at their labs and offices, they could check online to see that the morning tolls had been deducted from their prepaid accounts. The owners of cars without transponders will receive bills in the mail.

Siceloff: 919-829-4527 or blogs.newsobserver.com/crosstown or twitter.com/Road_Worrier/