The operator stayed on the phone with the man to reassure him until a patrol located his car - and drove the vehicle through the tunnel with him as a passenger, before sending him on his way. He was too scared to drive through the Dartford crossing.
Inspector Paul Sellwood, of the Kent Police roads policing unit, said: "This incident shows how seriously we take all calls we receive from members of the public."
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Any lingering showers clearing into tonight with a mostly dry but chilly night ahead. A cool but sunny start to Sunday.
Further heavy showers gradually clearing away this evening. Dry but chilly tonight, then dry with plenty of sunshine tomorrow.
Heavy showers turning potentially thundery this afternoon. Becoming dry but chilly tonight, then dry and sunny tomorrow.