Public Transport Accessibility Levels

Transport for London's (TFL) Public Transport Accessibility Levels (PTALs)

PTALS are a detailed and accurate measure of the accessibility of a point to the public transport network, taking into account walk access time and service availability. The method is essentially a way of measuring the density of the public transport network at any location within Greater London.

The current methodology was developed in 1992, by the London Borough of Hammersmith and Fulham. The model has been thoroughly reviewed and tested, and has been agreed by the London Borough-led PTAL development group as the most appropriate for use across London.

The measure therefore reflects:

• • Walking time from the point-of interest to the public transport access points;
• • The reliability of the service modes available;
• • The number of services available within the catchment; and
• • The level of service at the public transport access points - i.e. average waiting time.

It does not consider:

• • The speed or utility of accessible services;
• • Crowding, including the ability to board services; or,
• • Ease of interchange.

The PTAL methodology was developed for London where a dense integrated public transport network means that nearly all destinations can be reached within a reasonable amount of time. Research using the ATOS (Access to Opportunities and Services) methodology shows that there is a strong correlation between PTALs and the time taken to reach key services – i.e. high PTAL areas generally have good access to services and low PTAL areas have poor access to services.

Notes

6-digit references identify 100m grid squares.

The CSV file previously available on the Datastore is now only available via the TfL syndication website.

Current PTAL values can be calculated at TfL’s web site: www.webptals.org.uk