The effect of weather and climate on bicycle commuting

Abstract

This study presents data on the effect of both (short-term) weather conditions and (long-term) seasonal variation patterns on bicycle commuting patterns among several groups of tertiary students in the temperate climate of Melbourne, Australia. It questions some assumptions which have suggested that certain conditions are perceived by riders to make commuter cycling non-viable, and thus lead to a significant drop in numbers on days or periods when these conditions persist. While the data indicate that the assumptions have a foundation, the effects on the group surveyed are not as powerful as assumed. However, as students are an atypical group in several significant aspects, the results should only be transferred to non-student groups with some caution.

Introduction

In many western countries cycling has had somewhat of a resurgence over the last two decades after a period of being solidly eclipsed by motor cars. Some northern European countries (see, e.g. Ministry of Transport, Denmark, 1993) have positively encouraged more cycling, especially following the oil crisis of the mid seventies. Commuting cycling offers one means of reducing crippling import bills, is ecologically sound, while cycling for recreation is healthy exercise (Unwin, 1995).

However, any broad use of bicycles for regular business use is constrained by a number of factors, both practical and cultural. Regular commuter riding has particular problems of coping with some weather conditions: rain, wind, temperature, while sudden changes in conditions add a particular negative element to the commuting process. The necessity to carry bulky goods, the need to arrive well-groomed, age, health and gender/cultural mores also attenuate the possibilities.

It is often claimed that inclement weather is a strong disincentive to cycling, and in the context of Melbourne, that this is a particular issue. Claims are made, somewhat reinforced by official data (Bureau of Meteorology, 1975:2), that the erratic nature of Melbourne's daily weather can leave cyclists stranded. However, as the study reported here suggests, for many commuters these changes do not necessarily act as deterrents. Moreover, in the case of rain (a key deterrent), it need only stop for about 30 min to enable the majority of cyclists to complete their trip as they generally fall below this time span: in this study the mean travelling time was around 14 min, with a mean distance 7 km, while 75% of trips were less than 10 km and less than 20 min. The data arrayed in Table 1 and Table 2 accord generally with other studies involving trip time/length (Nankervis, 1981, Forester, 1983, NCDC/GHD, 1979, SBC, 1987:16,18; Wigan, 1983, Ohrn, 1975:14; Municipality of Copenhagen, 1989:8).

Of course, while it is generally assumed that weather (i.e., the short term changes) will have an effect on cycling, it is also important to make a distinction between weather and climate (the long term, seasonal changes). While there is a common perception that cycling conditions are worse in the winter, this may not be so. Fig. 1(a,b) indicates the mean lowest June–July temperature in Melbourne is 6 degrees, rainfall is evenly spread throughout the year and it is less likely than January for there to be days of winds above 15 kph (41 vs 46% chance). Consistent with this study are other studies (e.g. SBC/Spectrum, 1989:5) which indicated that only 2% felt `weather' (not defined) was a deterrent to cycling. In brief, it may be that climate and weather deterrents to commuter cycling in Melbourne may be more perceived than actual.