Traffic and the Environment

Achieving Air Quality Standards

Predicting Air Quality Levels

Effects of Existing Changes

It is important that we to recognise the crucial role transportation schemes can play in protecting the environmental well- being of ourthe city. The city centre has neither the road space nor the air space to accommodate an uncontrolled demand by cars vehicles and, at the same time, provide the quality environment needed to sustain thekeep attractingon of the city to residents, visitors, shoppers, tourists, office workers and other users toof the the city centre. It is generally accepted that reduced congestion leads to a better and healthier environment.

The Central Edinburgh Traffic Management proposals help the Council meet its obligations under The Environment Act (1995). The Act requires Councils to review and assess air quality in their areas to determine whether the objectives set in the UK National Air Quality Strategy and Air Quality Regulations 1997 are likely to be met by 2005. Councils are required to draw up practical transport strategies and land use plans for achieving these objectives.

The Council has also developed an air quality prediction module in the City Centre Paramics Traffic Model. This was developed to test various options within the Central Edinburgh Traffic Management proposals scheme options.

Predicted vehicle pollution is represented in this traffic modeling as a net, showing increasing and decreasing levels of Nitrogen Dioxide (NO₂) over the road network. The module can be used to demonstrate that increased levels of traffic do not necessarily mean increased levels of pollution - for instance, free flowing traffic is less harmful than queuing traffic.

We have monitored air quality throughout the life of the scheme. Monitoring sites were established in 1995 before traffic was banned from travelling eastbound on Princes Street. At the Council meeting in October 1997, it was agreed that a five-year monitoring programme be established from that point. The number of monitoring sites was revised in the spring of 2000 (as reported to Committee on 14 February 2000).

Noise and vibration monitoring was conducted before and after the eastbound ban on Princes Street was introduced in 1996. A report on Traffic Noise and Vibration Assessment was published in January 1997 which found that at two locations on Queen Street, where eastbound traffic volumes were effectively doubled, noise level increases were of "marginal significance". The results of the vibration survey indicated that there is no material impact from traffic vibration and the report noted that vibration levels required for structural damage are far above those that are generally caused by road traffic.