• Dunno if it helps but the A102 Blackwall Tunnel is a no no to ride bikes through, I was once sat in a queue (on a motorbike) waiting for the lights to change on the approach when 2 Boris bikes went past me on the tiny bit of pavement leading into the Southbound Tunnel, barriers came down and stopped 'em pronto. Also, the A282 Dartford River Crossing that includes both Tunnels and the Bridge is a no go cycling wise but you can summon a lift from the Maint crew from either side.

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