Washington, Jan 7 (IANS): People in the higher-income group leave their cars at home only when they find the neighbourhood attractive, not in the face of constraints such as neighbourhood density, new research has found.

On the other hand, people in the lower- and middle-income group are more likely to walk or bike when they find it difficult to drive, the findings showed.

"What drives these two groups of people to walk or bike is quite different," said senior study author Cynthia Chen, associate professor of civil and environmental engineering at University of Washington.

Dimensions of "attractiveness" that motivate the higher-income group include seeing other people when they walk in their neighbourhoods, the attractiveness of buildings and homes and having interesting things to look at, the study found.

"For the higher-income people, walking and biking is a largely result of choice, and our models show that the density of their neighbourhoods and most other things in their built environment, such as the accessibility of destinations, do not really matter as much to them," Chen noted.

"For the lower-income group, walking and cycling appears to be the result of constraints, in which case higher neighbourhood density and easy access to destinations are positively associated with more walking or biking," Chen said.

The findings are based on a random survey of 547 King County households who live in the highest- and lowest-density neighbourhoods around State Route 520 across Lake Washington.

The study will be presented at Transportation Research Board annual meeting to be held in Washington, DC, from January 10-14.