TRUCKS driving too slowly on expressways when there is no congestion pose a danger to other road users, so traffic police have upgraded their smart cameras in a bid to crack down on such dawdling.

At several points on the city’s expressways, new traffic cameras now watch out for trucks moving 20 percent or more below the lowest speed limit.

Since August 1, the cameras have caught over 120 offenders, police said yesterday.

Offenders are fined 200 yuan (US$30) and three points are deducted from their driving licenses.

At 3:45am on May 23, the driver of a heavy truck was killed after crashing into the rear end of another moving at only 28 to 38 kilometers per hour, while the lowest speed allowed on the expressway is 60 kilometers per hour, police said.

Police said these offenses usually take place at night due to overloading and tired drivers — most of the offenses caught on police cameras in August happened between 10:30pm and 5:30am.

The lowest speed recorded was 21 kilometers per hour on the Outer Ring Road at 5:52am on August 30.

Lower speeds are allowed during maintenance work, traffic accidents, congestion or bad weather.