Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2006 Sep 19:5:40.
doi: 10.1186/1476-072X-5-40.

Validation of travel times to hospital estimated by GIS

Robin Haynes  1 , Andrew P Jones, Violet Sauerzapf, Hongxin Zhao
Affiliations

Validation of travel times to hospital estimated by GIS

Robin Haynes et al. Int J Health Geogr. .

Abstract

Background: An increasing number of studies use GIS estimates of car travel times to health services, without presenting any evidence that the estimates are representative of real travel times. This investigation compared GIS estimates of travel times with the actual times reported by a sample of 475 cancer patients who had travelled by car to attend clinics at eight hospitals in the North of England.

Methods: Car travel times were estimated by GIS using the shortest road route between home address and hospital and average speed assumptions. These estimates were compared with reported journey times and straight line distances using graphical, correlation and regression techniques.

Results: There was a moderately strong association between reported times and estimated travel times (r = 0.856). Reported travel times were similarly related to straight line distances. Altogether, 50% of travel time estimates were within five minutes of the time reported by respondents, 77% were within ten minutes and 90% were within fifteen minutes. The distribution of over- and under-estimates was symmetrical, but estimated times tended to be longer than reported times with increasing distance from hospital. Almost all respondents rounded their travel time to the nearest five or ten minutes. The reason for many cases of reported journey times exceeding the estimated times was confirmed by respondents' comments as traffic congestion.

Conclusion: GIS estimates of car travel times were moderately close approximations to reported times. GIS travel time estimates may be superior to reported travel times for modelling purposes because reported times contain errors and can reflect unusual circumstances. Comparison with reported times did not suggest that estimated times were a more sensitive measure than straight line distance.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Comparison of estimated and reported journey to hospital times for patients who travelled by car.
Figure 2
Figure 2
Distribution of the differences between reported and estimated car journey time (minutes).
Figure 3
Figure 3
Differences between reported and estimated travel times as a function of distance to hospital.
Figure 4
Figure 4
Reported car travel times to hospital and straight line distance.
See this image and copyright information in PMC

References

    1. Higgs G. A literature review of the use of GIS-based measures of access to health care services. Health Services & Outcomes Research Methodology. 2004;5:119–139. doi: 10.1007/s10742-005-4304-7. - DOI
    1. Higgs G, White S. Alternatives to census-based indicators of social disadvantage in rural communities. Progress in Planning. 2000;53:1–81. doi: 10.1016/S0305-9006(99)00021-5. - DOI
    1. Martin D, Wrigley H, Barnett S, Roderick P. Increasing the sophistication of access measurement in a rural healthcare study. Health and Place. 2002;8:3–13. doi: 10.1016/S1353-8292(01)00031-4. - DOI - PubMed
    1. Lovett A, Haynes R, Sunnenberg G, Gale S. Car travel time and accessibility by bus to general practitioner services: a study using patient registers and GIS. Social Science and Medicine. 2002;55:97–111. doi: 10.1016/S0277-9536(01)00212-X. - DOI - PubMed
    1. Guagliardo MF. Spatial accessibility of primary care: concepts, methods and challenges. International Journal of Health Geographics. 2004;3 http://www.ij-healthgeographics.com/content/3/1/3 - PMC - PubMed

Publication types

LinkOut - more resources