TABLE 3 Empirical Results for Trip Duration Model,,
 Variable,Coefficient, t-statistic
 Constant,2.504,76.81
Trip purpose ,,
Production end (nonhome-based trip is base),,
Home-based ,0.213,16.16
Attraction end (work purpose is base),,
 School ,0.041,1.56
 Social-recreational,0.125,5.11
 Shopping,–0.299,–16.07
 Other,–0.215,–13.07
 Time-of-day variables (“evening” period is base),,
morning–a.m. peak/p.m. peak ,0.445,15.57
 a.m. offpeak/p.m. offpeak ,0.176,6.75
 Time of day and trip purpose interaction effects,,
 morning–a.m. peak/p.m. peak x nonwork,–0.155,–11.23
 a.m. offpeak/p.m. offpeak x social-recreational,–0.261,–8.94
 Zonal and trip-related attributes,,
Zonal size-related variables,,
Zonal area x 10–5,1.243,2.56
Zonal acreage in office space x 10–3,2.363,3.85
Number of people in service employment x 10–5,2.544,9.75
Zonal acreage in manufacturing facilities x 10–4,6.917,5.19
Zonal acreage in retail facilities x 10–3,–2.266,–4.82
Zonal acreage in institutional facilities x 10–3,–1.020,–2.54
Zonal nonsize-related variables,,
Zonal household density x 10–3,–1.612,–4.42
Median income of zone x 10–6,–2.576,–6.55
Presence of an airport or airport-related infrastructure x 10–2,5.342,2.56
Trip-related variables,,
Intrazonal trip,–0.777,–33.95
Intrazonal p.m. peak trip,–0.189,–5.08
Intrazonal shopping/social-recreational trip,0.158,6.12
 Number of observations,"19,455",
 Regression sums of squares,"2,737.09",
 Residual sums of squares,"11,058.14",
 Standard error of estimate,0.754,
 R2,0.198,
 Adjusted R2,0.198,