Tower Bridge bridge's upper walkways. The pedestrian walkways are above the river at high tide. The main bridge deck carries two lanes of road traffic between two low-level pedestrian walkways across both suspension spans and the opening bascule section of the bridge, with the walkways separated from the roadway by fences. The roadway passes through each of the two towers, whereas the low-level walkways pass around the outside of the towers. One of the chimneys on the bridge, which are often mistaken for lamp posts, connects up to an old fireplace in a guardroom of the Tower of London. It is long-disused.
Tower Bridge Rail stations are at Fenchurch Street and London Bridge. In the second half of the 19th century, an advertisement in the East End of London led to a hiring for a new river crossing downstream of London Bridge. A traditional fixed bridge at street level could not be built because it would cut off access by sailing ships to the port facilities in the Pool of London, between London Bridge and the Tower of London. A "Special Bridge or Subway Committee" was formed in 1877, chaired by Sir Albert Joseph Altman, to find a solution to the river crossing problem.