Motivating change in commuters’ mobility behaviour: Digital nudging for public transportation use

Figures & data

Figure 1. Research model and hypotheses.

Table 1. Attributes and attribute levels for CBC analysis (short/long commuting time).

Attributes	Attribute levels
Time until departure (in mins.)	<= 5/<= 15	6–10/16–30	11–15/>= 31
Travel time (in mins.)	<= 15/31–45	16–30/46–60	31–45/>= 61
Price (in euros)	2.50/10	3.50/20	4.50/30
Number of transfers	0	1	2/>= 2
Occupation	Low (vacant seats)	Medium (vacant seats uncertain)	High (no vacant seats)
Greenhouse gas emissions (in grams)	<= 150/<= 3,500	151–300/ 3,501–7,000	>= 301/>= 7,001

Figure 2. Exemplary choice set for private car commuters with a long travel time (translatated).

Table 2. Characteristics of the study participants.

Characteristics of participants	Sample with manipulation (n=287)	Control group (n = 224)	Total (n=511)
Gender
Female	128 (44.6%)	113 (50.4%)	238 (46.6%)
Male	157 (54.7%)	110 (49.1%)	270 (52.8%)
Diverse	2 (0.7%)	1 (0.5%)	3 (0.6%)
Age
<25	52 (18.1%)	30 (13.4%)	82 (16.1%)
25–34	123 (42.9%)	78 (34.8%)	201 (39.3%)
35–44	66 (23.0%)	79 (35.3%)	145 (28.4%)
45–54	34 (11.8%)	26 (11.6%)	60 (11.7%)
>= 55	12 (4.2%)	11 (4.9%)	23 (4.5%)
Net income per month (in €)
<= 1,300	47 (16.4%)	34 (15.2%)	81 (15.9%)
1,301–2,000	67 (23.3%)	64 (28.6%)	131 (25.6%)
2,001–3,600	134 (46.7%)	107 (47.8%)	241 (47.2%)
3,601–5,000	28 (9.8%)	15 (6.7%)	43 (8.4%)
>5,000	11 (3.8%)	4 (1.8%)	15 (2.9%)
Use of Mobility Apps for Commuting
Never	122 (42.5%)	104 (46.4%)	226 (44.2%)
Rarely	81 (28.2%)	54 (24.1%)	135 (26.4%)
Sometimes	36 (12.5%)	34 (15.2%)	70 (13.7%)
Often	25 (8.7%)	11 (4.9%)	36 (7.0%)
Always	23 (8.0%)	21 (9.4%)	44 (8.6%)

Table 3. Differences in choice rates (in %) and standard errors for the recommended public transport trip option.

Differences in choice rates for the treatment groups compared to the control groups
All participants
−0.4 (0.1878)
Short travel time		Long travel time
2.7* (0.1927)		−5.1* (0.1760)
Non-app users	App users	Non-app users	App users
4.3* (0.1982)	1.0 (0.1975)	0.0 (0.1683)	−9.0** (0.1800)

*p< 0.10, **p< 0.05, ***p< 0.01

Table 4. Relative importance of the attributes (in %) for the control groups.

Attribute	Short travel time		Long travel time
	Non-app users users	App users	Non-app users	App users
Time until departure	10.7	5.4	14.9	9.5
Travel time	32.7	39.6	13.6	15.9
Price	18.6	14.2	7.4	29.1
Number of transfers	18.1	24.9	18.0	12.9
Occupation	12.7	10.2	15.0	17.5
Greenhouse gas emissions	7.1	5.7	31.1	15.1

Table 5. Relative importance of the attributes (in %) for the treatment groups.

Attribute	Short travel time		Long travel time
	Non-app users	App users	Non-app users	App users
Time until departure	5.4	7.0	6.5	6.5
Travel time	35.3	36.3	13.5	23.8
Price	11.6	12.0	20.0	13.9
Number of transfers	21.2	17.9	13.4	19.4
Occupation	11.9	13.0	28.0	27.1
Greenhouse gas emissions	14.5	13.8	18.7	9.4

Table 6. Overview of hypotheses and study results.

Hypotheses	Findings
Hypothesis 1: Recommending a public transport trip option to private car commuters increases the likelihood that they will choose the option.	Not supported
Hypothesis 2: The effect of recommending a public transport trip option to private car commuters is larger for commuters with a short travel time.	Supported
Hypothesis 3: The effect of recommending a public transport trip option to private car commuters is larger for mobility app users compared to non-users.	Not supported

Table A1. Public transportation trip attributes and number of selection as relevant attribute in the pre-test.

Public transport trip attribute	Number of selection as relevant attribute
Price	21
Travel time	20
Means of transportation (e.g. bus or train)	3
Transfer time	4
Occupation	10
Reliability/Possibility of delay	8
Time until departure	11
Time until arrival	9
Seat reservation available	5
Number of transfers	23
Bonus points available	1
Wi-Fi available	9
Greenhouse gas emissions	13
Connection ticket included	5
More	2

Table A2. Differences in choice rates (in %) and standard errors for the recommended public transport trip option.

Differences and choice rates of the treatment group and the control group
All participants
−0.4 (14.5/14.1) (0.1878)
Short travel time		Long travel time
2.7* (14.8/17.5) (0.1927)		−5.1* (13.1/8.0) (0.1760)
Non-app users	App users	Non-app users	App users
4.3* (10.8/15.1) (0.1982)	1.0 (18.4/19.4) (0.1975)	0.0 (8.1/8.1) (0.1683)	−9.0** (17.0/8.0) (0.1800)

Note: (*p< 0.10, **p< 0.05, ***p< 0.01).