Modal Choice for the Driverless City: Scenario Simulation Based on a Stated Preference Survey

Table 5

Error component Mixed Logit models (mandatory and leisure purposes).

Variable name (alternative)	Error component Mixed Logit with panel effect (ECML): mandatory trip		Error component Mixed Logit with panel effect (ECML): leisure trip
	Estimate	z-test	Estimate	z-test
Random parameters in the utility function
CT (AV, SAV, PT)	−3.273	−11.61	−2.104	−7.22
TT (AV, SAV, PT, BIKE, WALK)	−0.184	−6.90	−0.126	−7.10
WT (SAV, PT)	−0.697	−8.40	−0.539	−7.57
Nonrandom parameters in the utility function
SAV	−1.218	−4.22	2.399	7.18
PT	−0.013	−0.02	2.567	4.50
BIKE	−2.442	−2.94	1.292	2.24
WALK	−0.289	−0.36	2.884	4.81
Gender (AV, SAV); (1 = female)	—	—	−1.421	−3.11
Age 25–65 (AV); (reference: <25 years)	−0.543	−1.96	2.084	6.02
Age >65 (AV)	−2.035	−5.68	2.204	6.66
Age >65 (BIKE)	−4.291	−3.70	—	—
Age >65 (WALK)	−4.423	−3.36	2.579	9.54
Income >2500 € (AV); (reference: <900 €)	1.341	3.38	—	—
Income >2500 € (BIKE, WALK)	—	—	2.096	3.49
CAR (AV, SAV); (1 = car available)	−2.423	−2.96	—	—
CAR_USED (AV, SAV); (1 = car used in the most frequent trip)	2.809	5.85	—	—
SCENARIO_M (AV, SAV); (1 = medium-distance scenario)	3.489	7.28	2.047	7.36
SCENARIO_L (AV, SAV); (1 = long-distance scenario)	5.807	7.40	2.536	5.62
SCENARIO_M (PT)	2.448	5.23	0.602	1.73
SCENARIO_L (PT)	4.163	5.56	1.802	4.10
COMFORT (SAV,PT); (1 = High comfort)	0.452	2.44	—	—
COMFORT (PT); (1 = high comfort)	—	—	0.383	1.58
UT (BIKE); (1 = terrain with slopes)	−0.639	−1.86	—	—
Interactions of random parameters with socioeconomic variables
Interaction of CT and gender (AV, SAV, PT)	—	—	0.478	1.92
Interaction of CT and CAR_USED (AV, SAV, PT)	2.714	7.50	0.710	3.10
Interaction of CT and income>2500 € (AV, SAV, PT)	—	—	1.186	3.59
Interaction of TT and income>2500 € (AV, SAV, PT, BIKE, WALK)	0.054	3.39
Interaction of TT and CAR_USED (AV, SAV, PT, BIKE, WALK)	0.074	3.64	0.034	2.79
Interaction of WT and gender (SAV, PT)	0.325	4.58	0.205	3.43
Interaction of WT and income >2500 € (SAV, PT)	0.208	4.08	0.165	2.50
Interaction of WT and CAR_USED (SAV, PT)	0.211	3.24	—	—
Deviation of the distributions of the random parameters
Sigma CT (AV, SAV, PT) (T)	3.273	11.61	2.104	7.22
Sigma TT (AV, SAV, PT, BIKE, WALK) (T)	0.184	6.90	0.126	7.10
Sigma WT (SAV, PT) (T)	0.697	8.40	0.539	7.57
Deviation of the random latent effects
Sigma (AV, SAV)	4.661	10.46	2.324	8.97
Sigma (BIKE, WALK)	2.234	10.23	2.143	7.95
Log-likelihood	−1375.89	−1569.20
	0.391	0.302
	0.331	0.293
Log-likelihood (constants only)	−2055.55	−2218.71

Alternative specific constant of the alternative.