According to Westminster Living Streets:
“In preparation for the project to convert Baker Street and Gloucester Place to two-way working, TfL has just presented an Air Quality Assessment of the area to Westminster Council. Monitors on Marylebone Road and Oxford Street had already revealed those two to be among the most polluted streets anywhere. The new study shows that every street in the area, not just those two, has above the legal levels of pollution due to road traffic.
Some objectors to two-way operation feared that it would improve the commercial streets by redistributing the traffic over less-polluted residential areas. As of this week it is clear that wouldn’t work. With or without the two-way scheme, traffic in the whole area must be quickly reduced now that the Supreme Court has thrown out the government’s plea for more time. Westminster Council (as subcontractor to the TfL) had prepared plans for the two-way scheme using a model that assumed the same level of traffic in 2018 as today. That is no longer a feasible scenario.
Either ULEZ, or the SuperULEZ now being studied by TfL as a replacement, or some other means such as road pricing must reduce motor traffic. The result is that there will be more road capacity which can be recycled, most obviously for separate cycle lanes because the scheme already caters for the increased number of pedestrians who will arrive by public transport to live, work, shop, and be entertained in the area.
Westminster Council have not yet commented on the new Air Quality Assessment.”