7. Environmental impacts on Oxford Street
7.1 Noise and Pollution
The withdrawal of motorised traffic from Oxford Street meets the objective of reduction of noise and pollution because trams are quiet and produce no local emissions. With an additional requirement for the buses to be low emission vehicles also the pollution problem on bus-only streets (e.g. Charing Cross Road) can be tackled. Experience from other cities (Grenoble, Manchester) shows a vast improvement of environmental conditions.
The current situation on Oxford Street has to be compared with the situation in areas where Light Rail systems and pedestrianisation are implemented. Quantitative data is not available here so that measurement of noise and pollution emissions is necessary in order to perform a detailed comparison. But qualitatively these two different situations can be experienced quite easily (e.g. on Oxford Street and in Manchester or Düsseldorf) and then the positive change to environmental conditions is obvious.
While on Oxford Street fumes and smoke from vehicle engines fill the atmosphere (it can be seen and smelled) and the noise emissions make any conversation difficult in the pedestrian areas of Manchester and Düsseldorf, accessible by tram, the opposite can be experienced. These are attractive places to go for walking and shopping.
7.2 Visual Impacts
When evaluating the visual impacts two aspects have to be considered. First the visual impacts of buses (and taxis) on Oxford Street as it is the present situation and secondly the visual impacts imposed by the tramway as it will be after implementation of the scheme.
Red buses and black cab are evaluated differently. Tourists might appreciate them as famous London landmarks and not suffer from their environmental impacts. But those who have to live with them, the citizens of London who go to Oxford Street from time to time, are annoyed by their impacts as the results from the questionnaire survey show. On Oxford Street itself it can be seen that the double decked buses block the view on attractive buildings, let alone the overcrowding that prevents people from looking at the streetscape.
Pedestrianisation would take away red buses and black cabs, thus give free view on the streetscape. A new visual impact is introduced by the tramway in form of the vehicles itself and in form of the power supply by overhead wires. The Light Rail vehicles will be less frequent than the current bus services altogether, say every 5 minutes in the peak, which is due to its higher capacity. As the Grenoble example shows they can also be design to blend into the surrounding streetscape so that visual impact would be marginal.
More consideration has to be taken about power supply equipment, which is definitely not invisible, so that a careful design is necessary to reduce visual impacts. A low voltage power supply makes the design of small insulation and a single wire arrangement possible, which results in a lower weight that allows minimum supporting structures. The Manchester example shows how visual impact can be minimised. The city centre section of Metrolink runs partially along the front of historic buildings (e.g. at St. Peters Square), where the overhead wire structures are designed not to destroy the view on the streetscape.
7.3 Severance
Pedestrianisation of Oxford Street and provision of access by tram will eliminate the severance effect of the current traffic. Trams will have a clearly defined path and operate in intervals (e.g. 5 min) so that there are enough gaps for pedestrians to move around the whole street. The overall design of the pedestrianised area will encourage the use of the street as a place to stay and walk around. The closure of Charing Cross Road for private vehicles reduces the traffic through the West End and therefore minimises the severance.
Experience from other cities shows how a well designed Light Rail system can enhance a city centre. Barry gives examples from San Diego, Nantes, San Jose, Utrecht and Portland. Grenoble demonstrates Light Rail as a total system where the streetscapes have been transformed into a model for city living (Barry).