On average, 88.1 percent of drivers use seat belts while on ordinary roads and 97.1 percent do so on expressways, according to a survey released Thursday by the National Police Agency and Japan Automobile Federation.

Drivers and front-seat passengers are required to buckle up.

Nagasaki Prefecture had the best record, where 96.4 percent of the drivers monitored were wearing seat belts, while 100 percent of drivers on expressways in Yamagata Prefecture had buckled up.

Chiba ranked worst, logging just 78.8 percent compliance on ordinary roads.

Launched Oct. 1, the 10-day survey covered 361,393 vehicles on 818 roads and 127 highways across the nation.

Nationwide, 75.2 percent of front-seat riders wore seat belts on ordinary roads, and 90.6 percent on expressways.

Just 6.7 percent of rear-seat passengers buckled up on ordinary roads, rising to 9.3 percent on expressways.