For those involved in labour market analysis and planning, it is useful to be able to use data for zones that are labour market areas. To meet this need, the zones must be defined so that the bulk of their resident population also work within the same area. Defining labour market areas requires the analysis of commuting patterns, and the Office for National Statistics (ONS) has worked with Newcastle University to apply a complex allocation process to define a set of Travel to Work Areas (TTWAs).

The fundamental criterion is that, of the resident economically active population, at least 75 per cent actually work in the area, and also, that of everyone working in the area, at least 75 per cent actually live in the area.

The resulting pattern is that, although the definitive minimum working population in a TTWA is 3,500, many are much larger - indeed, the whole of London and surrounding area forms one TTWA.

The 243 current TTWAs were defined in 2007 using 2001 Census information on home and work addresses, and are based on Lower Layer Super Output areas in England and Wales, data zones in Scotland, and Super Output Areas in Northern Ireland.

We see once again a reduction in the number of TTWAs as the trend in more and longer distance commuting increases: in 1991 there were 314 TTWAs and in 1981, 334. See background and a description of some example changes to TTWAs over the past 10 years.
See data relating to the 2001-based TTWAs.

The description of Methodology (34Kb, pdf)

If you have any questions on the 2001-based TTWAs please email us on [email protected]

TTWA names and codes (link)

2001 – based TTWA allocations (607Kb, zip)

Final Project Report: Travel-to-Work Areas: th3 2007 review (2.3Mb, zip)

In addition the Office for National Statistics has been developing other outputs to help people understand commuting patterns. For more information please see the Commuting Statistics page.