air pollution concentrations

[JDWoodcock]

the AP concentrations are going up at the link level in Go Dutch. This is clearly not right. We need to check the other scenarios and crucially check logic of implementation from traffic volume to emissions and from emissions to concentrations. Marina is looking at this but others need to prioritise helping her

[JDWoodcock]

update https://content.tfl.gov.uk/speed-emissions-and-health.pdf
the current model might be running correctly as it could be due to other features in the emissions calculation that off set reductions in distance by lower speeds. However, it is still surprising and needs checking. What we want is a clear process to see what is changing in terms of traffic and emissions by road type and maybe day of week. We can see if there is an error and decide if we want to make any changes