andrewc

I had a look for myself just now on a Saturday morning and Grove Vale was running freely. Apart from the queue to the petrol station! That's not to say that that there is no congestion at other times...just not this morning.

Well if pollution from a busy road affects everyone in an area then...we are are all affected whichever road we live in. So if pollution rises in total then we are all affected adversely and I guess the reverse would be true. But I don't know how car fumes spread. I wouldn't like to guess.

Is it true to say that pollution from cars spreads around in an area? Is there any data on this? If so, then the way we discuss the issue would change.

Agreed.

East Dulwich Grove at 9.30am this morning

This morning at 9.30am

I'm not sure there is an "anti-car lobby" anymore in the sense that all the major UK political parties (apart from the Brexit Party) promoted themselves as supportive of reduced car use/increased walking and cycling in their latest manifestos. However I agree that even the most ardent 'active travel' supporter would not want to increase emissions by increasing standing traffic. https://www.bikebiz.com/cycling-to-the-polls-what-does-each-party-offer-for-cyclists/

Today at 3.45pm

I let go of the offices I rented in town and now use the living room for face to face and the bedroom for me desk (in the bay window). Not going back. Time for a change.

I am certainly incapable in answering any questions on traffic management because I have no training in the subject. .

Are there any studies that support the idea that more roads reduce traffic?

This is a meta analysis of 33 studies on traffic calming. "the meta-analysis shows that area-wide urban traffic calming schemes on the average reduce the number of injury accidents by about 15% https://www.sciencedirect.com/science/article/abs/pii/S0001457500000464

In my search for evidence for or against road closures, this link may interest some. I am not cherry picking here. Just googling and posting up what I find, as someone who is not an expert but interested. https://en.wikipedia.org/wiki/Induced_demand Or maybe this one https://ec.europa.eu/environment/pubs/pdf/streets_people.pdf

I would happily parade down the streets protesting at the road closures if I felt that helped. However I cannot find any studies that support that action. They may exist but I cannot find them. The latest study I posted up was from Edinburgh Napier University and is dated 10 July 2020. It may be that in Dulwich the road closures do not have the same positive effect as evidenced in studies.

Politicians are being sued for not reducing pollution. The Paris agreement on emissions means that countries are mandated to comply. Not taking action is not an option. I know that many on this thread think that polution will go up with road closures but all the evidence is to the contrary. I guess this is why politicians are getting involved.

The Edinburgh Napier University Study is dated July 10 2020.

Studies indicate that on average, over-all traffic reduces by 11% (with a road closure). Is there any evidence that this drop in car use would not be a benefit to all local streets in terms of air quality?

Here is a recent study on the effect of school street closures. https://www.napier.ac.uk/about-us/news/school-street-closures

This study on how road closures reduce overall traffic levels is worth a read. https://www.napier.ac.uk/about-us/news/school-street-closures

Are there any studies that support the case that a reduction in traffic of 11% in an area is a benefit to the whole community? Or does it just benefit those on the quieter roads. I don't know if improved air quality is shared among connecting streets.

Here is a the introduction to the study (Generated Traffic and Induced Travel) below. Traffic engineers often compare traffic to a fluid, assuming that a certain volume must flow through the road system, but it is more appropriate to compare urban traffic to a gas that expands to fill available space (Jacobsen 1997). Traffic congestion tends to maintain equilibrium: traffic volumes increase to the point that congestion delays discourage additional peak-period vehicle trips. Expanding congested roads attracts latent demand, trips from other routes, times and modes, and encourage longer and more frequent travel. This is called generated traffic, referring to additional peak-period vehicle traffic on a particular road. This consists in part of induced travel, which refers to absolute increases in vehicle miles travel (VMT) compared with what would otherwise occur. https://www.researchgate.net/publication/235360397_Generated_Traffic_and_Induced_Travel_Implications_for_Transport_Planning

Are there any studies that show that 'overall' traffic reduction does not happen as a result of road closures? Or, contrariwise, that adding roads to a network reduces road use?

Here is a the introduction to the study (Generated Traffic and Induced Travel) below. Traffic engineers often compare traffic to a fluid, assuming that a certain volume must flow through the road system, but it is more appropriate to compare urban traffic to a gas that expands to fill available space (Jacobsen 1997). Traffic congestion tends to maintain equilibrium: traffic volumes increase to the point that congestion delays discourage additional peak-period vehicle trips. Expanding congested roads attracts latent demand, trips from other routes, times and modes, and encourage longer and more frequent travel. This is called generated traffic, referring to additional peak-period vehicle traffic on a particular road. This consists in part of induced travel, which refers to absolute increases in vehicle miles travel (VMT) compared with what would otherwise occur. https://www.researchgate.net/profile/Todd_Litman/publication/235360397_Generated_Traffic_and_Induced_Travel_Implications_for_Transport_Planning/links/5a69f90d4585154d15465728/Generated-Traffic-and-Induced-Travel-Implications-for-Transport-Planning.pdf

This is worth a read too. The effect of a road closure in New York. https://www.nytimes.com/2019/10/13/nyregion/14th-street-cars-banned.html

This makes interesting reading. A summary of 70 traffic studies and the average 'traffic evaporation' measured. https://www.onestreet.org/images/stories/Disappearing_traffic.pdf