The four-week trial starts on Friday 31st July on Route 188 (North Greenwich to Tottenham Court Road) and is the latest stage of TfL’s Bus Safety Innovation Challenge. Every time the doors close, passengers will hear the classic Routemaster ding-ding, followed by the announcement: “Please hold onto the handrails”. TfL says around three-quarters of all slips, trips and falls on London buses involve passengers who weren’t holding onto a handrail. Researchers will monitor how well the system performs on Route 188 before it is expanded to an additional 10 bus routes. The wider trial will help TfL decide whether audio cues should become a regular feature on London’s buses.