A new study of driving behavior in the United States in relation to electric vehicle adoption attempts to address widespread concerns regarding range anxiety. Two doctoral students at the School of Engineering and Applied Science at Columbia University conducted an in depth study of household travel data, collected in 2009, to identify patterns and factors which influence the distances of average household vehicle trips. Through this research the students aimed to determine whether or not the average range of current electric vehicle models would prove sufficient for most vehicle travel.

The study employed a two-fold method to address concerns of range anxiety, upon completing a statistical analysis of the distances driven, the researchers, firstly, compared these distances with the stated range of current, 2011, electric vehicle models and, secondly, assessed data concerning usage patterns to determine how frequently vehicles could be charged. This combination of pure range with realistic expectations for charging frequency enables the study to draw certain conclusions regarding the likelihood of drivers falling victim to an empty battery mid-trip.

On the basis of their statistical analysis of driving data, the researchers were able to determine that the average distance driven in a day, by a single car, was below 60km in urban areas and below 80km in rural areas. Furthermore, average commuting distances were found to average a mere 20km. This data was then assessed alongside data concerning usage pattern, which determined that a minimum of 92% of all cars were not in use between the hours of 17:00 and 7:00, seemingly confirming existing theories regarding daily usage patterns. Taken together, this data suggests that even those vehicles with shorter estimated ranges, such as the Chevy Volt’s 64km, would be sufficient for residents of urban areas. However, the study does point out that an electric vehicle’s true range is dependent on such a vast variety of factors, such as climate conditions, driving speed and style and the use of onboard equipment, such as air-conditioning or the stereo.

In addition to serving as an informative assessment of travel patterns in relation to electric vehicle adoption, the study also provides some insights regarding efficient urban planning. By dividing its analysis of driving patterns into urban and rural environments as well as the reasons trips are undertaken, the study serves to identify the most common reasons for trips as well as their average lengths, thereby enabling an assessment of which services should be located nearest to residents. The study’s analysis of trip purpose data, as presented in the table below, shows that the longest distances traveled are those to work and social or recreational events and the most frequent trips are those between work and home and to run errands. The significantly long distances traveled to medical centers, when compared to other essential services such as errands and meals, suggests that these services should be more localized and situated closer to residential areas where possible.


Trip Purpose

All trips

Unweighted count (%)

Mean (km)

Percentile 95 (km)

Home

34%

14.96

48.28

Work

13%

19.47

57.94

School

4%

11.26

38.6

Medical

2%

17.22

54.72

Errands

22%

9.8

32.19

Social/Recreational

9%

24.78

80.47

Family/Obligations

3%

17.7

56.32

Transport someone

5%

12.55

41.84

Meals

7%

11.26

35.4

Other

0%

24.62

75.64

 

 

 

 

 

 

 

 

Thus, while the study does not come down firmly on whether or not the range of current electric vehicle models is sufficient to quell consumers’ range anxiety, it does make a strong case for the attractiveness of range extended and hybrid vehicles.

Source: "EV range requirements and Driving Statistics"

Read more: Article on EV range anxiety in National Geographic Magazine

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