BOSTON ( TheStreet) -- If you'd rather spend an hour in a dentist's chair than in a traffic jam, here's a look at five U.S. cities you definitely don't want to move to. "Sitting in traffic is like watching paint dry -- it might only take seven minutes, but it sure seems like longer," says Jim Bak of traffic-monitoring firm Inrix, which recently released its sixth-annual Traffic Scorecard. Inrix, which beams real-time traffic information to factory-installed global-positioning systems in cars built by Audi, BMW and other brands, ranked rush-hour traffic in America's 100 largest cities by analyzing data collected daily from some 100 million vehicles. The firm found that rush-hour traffic rose 4% on average in the nation's biggest metro areas during 2013's first quarter, with congestion getting worse in 61 of the 100 communities studied. Bak says gridlock increased because many metro areas' economies are recovering, boosting the number of people who have jobs to drive to. He says better employment numbers lead in turn to more consumer spending, which increases the number of delivery trucks on the road to keep local businesses stocked with goods. "It's a good news/bad news situation for drivers," Bak says. "It's no fun spending more time in traffic -- but at least it means that your city's economy is humming, some of your friends who lost jobs during the recession are back at work and your 401(k) is probably on the rebound." Here's a look at the five cities that Inrix found had the worst rush-hour traffic during 2013's first quarter. Researchers based their rankings on Inrix's Travel Time Index, a percentage figure that reflects how much time traffic adds to the average rush-hour trip. For instance, someone living in a city with a 30% Travel Time Index can expect rush-hour journeys to take 30% longer than the same trips require during traffic-free periods.