SMILE next time you board a tram, because a candid camera may be ensuring the doors are not slammed in your face. Hongkong Tramways is testing closed-circuit television systems to improve safety for boarding passengers. Five trams have been fitted with the system, which has a camera mounted over the rear entrance and a video monitor in the cabin. Drivers watch the screen, checking passengers are safely aboard before closing the doors and driving off. General manager Frankie Yick Chi-ming said the system could also spot people trying to flee without paying. The company may also remove the rear turnstiles. 'Some passengers have also complained the turnstiles are inconvenient, so if we remove them the CCTV system could ensure no one went out of the entrance door without paying,' Mr Yick said. The trial will run for one or two months.