This project objective was to refine the ONS Travel-To-Work Areas for Cambridge to make them more appropriate for housing planning purposes.
The objective of this project was to refine for housing planning purposes the recently published ONS Travel-To-Work Areas (TTWA) for Cambridge. The existing approach to TTWAs was problematic because it did not allow for areas to overlap; each area was assumed to be discrete – to feed into only one city or central hub. This approach, which allowed for overlap, has the potential to make TTWAs more useful for housing planning purposes.
Experimental review of the Cambridge Travel to Work Area (TTWA) as a tool for informing local housing policy - including a study of the Ely housing market in the context of the Cambridge TTWA
Travel To Work Areas are used primarily to understand local labour markets, but are also used in housing planning. However, TTWAs do not allow for overlap. Taking Cambridge as their example, Chihiro Udagawa and Dr Paul Sanderson identified commuting areas for Cambridge that lie within the boundaries of other employment hubs. Their study suggested that care should be taken when using TWAs for housing planning purposes.
A Travel-to-work Area (TTWA) theoretically represents a self-contained labour market area in which all commuting occurs within the boundary of that area. It has been re-defined once a decade when analyses on commuting patterns drawn from the UK Censuses were completed. In December 2015, the Office of National Statistics (ONS) published TTWAs based on the 2011 Census results.
TTWAs are used primarily to aid understanding of labour markets across the UK. However, residential location and commuting patterns can also contribute to understanding local housing markets. The conventional assumption is that local labour markets are spatial proxies for housing markets. Indeed, housing professionals have been employing TTWAs in this way in their strategic plans.
One of the issues in using existing TTWA s in this way is that they do not allow for overlap. Consider a household with two earners, one of whom is commuting within the TTWA while the other is commuting to a business hub outside their TTWA. For example, Cambridge TTWA has now expanded as far south as Hertford and Harlow - settlements containing many London commuters.
Taking Cambridge as our example we attempt in this paper to experimentally identify commuting areas for Cambridge that lie within the boundaries of other employment hubs, such as Ely. In this way we can start to address the reality that TTWAs, certainly in terms of local housing markets, are not discrete - they overlap.