The Role of Parking in Successful Urban Centers: New Report from London

London Council commissioned a report on the role parking plays in ongoing success of urban centers. Here is a link to the report. Here are the findings:

The review of the academic literature and other reports showed that there was relatively little research carried out into the link between parking and urban centre success. Where there was research, it was often not backed up by survey data or other robust evidence.
However, where there was research, the main findings were as follows:
1) More parking does not necessarily mean greater commercial success. A well managed parking scheme, where spaces ‘turn over’ frequently can help to increase the number of visitors coming to a town centre and thereby help business.
2) There is no such thing as ‘free’ parking. The costs of developing and maintaining parking
spaces and then enforcing proper use to ensure good traffic flow have to be borne by
somebody. In the case of local authority operated parking (on street or off street) any costs
that are not covered by parking revenue falls to local Council Tax payers.
3) Shopkeepers consistently overestimate the share of their customers coming by car. In
some cases, this is by a factor of as much as 400%. In London, as well as other cities, the
share of those accessing urban centres on foot or by public transport is much greater. Walking
is the most important mode for accessing local town centres; public transport is the most
important mode for travel to international centres, such as Oxford Street.
4) Car drivers spend more on a single trip; walkers and bus users spend more over a
week or a month. In 2011, in London town centres, walkers spent £147 more per month than
those travelling by car. Compared with 2004, spending by public transport users and walkers
has risen; spending by car users and cyclists has decreased.
5) A good mix of shops and services and a quality environment are some of the most
important factors in attracting visitors to town centres. If both these are poor, then
changes to parking or accessibility are very unlikely to make a town centre more attractive.
6) There is very little evidence of the impacts of parking on the night time economy. This is
an area that needs more research.
7) Boroughs collect a lot of data on parking but there is less information available on town
centre economic factors. Finding ways to coordinate data collection across departments
could be helpful to monitor the impacts of parking policies.

I haven't read the whole thing closely but it looks like a nice review of the state of the literature with some new survey data to support their assertions.