|From:||Tower Hill (TQ334807)|
|To:||Bricklayers Arms (TQ329790)|
|Length:||1.2 miles (1.9 km)|
|Meets:||A3211, A1211, A1210, A1203, A200, A2198, A2205, A2206, A2, A201|
|Route outline (key)|
The A100 is one of the most famous roads in the world owing to its route across Tower Bridge. However, it's far better known by name than number; few people would be able to place the A100 on a map of London.
The road starts at Tower Hill, London EC4, on the A3211. This is a complicated junction where several roads seem to meet, cross and end within a very small area. There's a bus-only TOTSO before the A100 runs along the elevated approach road between the Tower of London and St Katherine Docks to reach Tower Bridge itself. On the far side of the river the road crosses the A200 at traffic lights then goes under the railway line east of London Bridge station. It bends to the right and ends at the Bricklayers Arms junction, where it meets the A2 and A201.
The A100 is a primary route, part of the inner ring road, and consequently part of the Central London Congestion Charging Zone boundary. As such it is one of only three fixed link crossings between the Congestion Charging Zone and the eastern boundary of London - and that's assuming the bridge isn't open to allow boats to pass along the river. The others are the A101 (Rotherhithe Tunnel) and the A102 (Blackwall Tunnel).
London Bridge was the easternmost crossing on the River Thames for hundreds of years but development downstream in the 19th century meant that further crossings were required. However, a conventional bridge was out of the question as traffic still needed to pass on the river. The bascule bridge was built to allow traffic to cross without needing to climb onto a high-level bridge but still allowing river traffic.
Tower Bridge opened in 1894. Ever since then, it has been possible to buy a souvenir of Tower Bridge, making it one of the few roads you can buy in model form.
In 2003, it became a border of the London Congestion Charge zone.
The bridge still opens regularly and river traffic has priority over road traffic. However, river passages must be booked 24 hours in advance.