The Ballinasloe NCT centre is the only one in the county where more cars pass their initial test than fail.
Almost 17,000 drivers took their car for a test there last year, and 59 percent of cars passed their intial test - the highest rate in the county.
The next best initial test pass rate is in Tuam, where over 20,000 cars were tested, with a pass rate of just below 50 percent.
Despite being on opposite ends of the scale when it comes to demand, Clifden and Galway city had pass rates of 46 and 47 percent, respectively.
