Influence of Demographics and Urban Form on Mass Transit Use

Transportation Crossroads: Transportation Crossroads: Influence of Urban Area Form and Influence of Urban Area Form and

Demographic Composition on Mass TransitDemographic Composition on Mass Transit Parfait Gasana

University of North Carolina at Chapel HillSouthern Sociological Society Meeting

April 1-4, 2009 New Orleans, LA

Images of Jefferson City, MO bus (http://www.jeffcitymo.org); Houston rail system (http://www.fhwa.dot.gov/); New York subway (http://www.inhabitat.com)

Research Question Research Question

How do urban area form and demographic composition affect mass transit use (particularly motor bus, light/heavy rail systems)?

Background and Research ContextBackground and Research Context

Economic Restructuring: Shift from Manufacturing to ServicesUrban Policy: Highways, Housing, Land-Use ZonesDemographics: Aging, Single Households, Minorities, Low-Skilled vs. Professional WorkersOutcomes: Automobile Reliance, Transit Scarcity, and Infrastructure, Environment, Energy, & Equity Issues

Research MethodsResearch Methods

Unit of Analysis: Urbanized Area (UZAs) (No. = 360) yi {per capita trips, miles} = β0 + β1i {demographic variables} + β2i {urban characteristics} + β3i {dollar amts.} + µi

Dep. Vars. = {per capita trips, miles} (from National Transit Database, 2000-2007)Indep. Vars. = {demographic variables, urban area characteristics, dollar amounts} (from U.S. Census, 2000)Estimation Models: OLS, Median Regression, and Panel Regression (FE & RE)

Demographic Variables (Source: U.S. Census)AgeYoung Age (0-25) 0.37Working Age (26-64) 0.51Old Age (65 – up) 0.13

Household Size One 0.27Two or Three 0.49Four or more 0.24

Commute TimesLow (0-14 min.) 0.39Middle (15-29 min.) 0.13High (30-44min) 0.08 Really High (45-90 min.) 0.02

RaceWhite 0.73Non-white 0.27

EducationNo H.S. Educ 0.18H.S. Educ. 0.28Some College 0.29BA Educ. 0.16Prof. Educ. 0.09

Region Northeast 0.14South 0.23West 0.25Midwest 0.39

Poverty Pct. 0.13 OccupationWhite-Collared 0.33Service Sales 0.43Blue-Collared 0.23

Car Ownership 0.63

Urban Area CharacteristicsUrban Area CharacteristicsPopulationCentral Place DensityCity AgeUA Population / State Road

SourcesU.S. Census U.S. Census MSN Encarta FHWA, USDOT

Dollar FiguresLog of Home ValueLog of Govt. FundLog of Gas Prices

U.S. Census National Transit DatabaseEIA, Dept. of Energy

Descriptive StatisticsDescriptive Statistics

Population TrendsPopulation Trends

Density TrendsDensity Trends

Per Capita Transit Trips 2002 2003 2004 2005 2006 2007 | Coef. Coef. Coef. Coef. Coef. Coef. No. | 336 350 355 365 367 370 Adj. R-sq | 0.469 0.470 0.479 0.495 0.405 0.464 ------------------------------------|-----------------------------------------------------------------------------------------------------------------

Old Age | 92.72 93.95 86.08 112.7* -1.106 141.0** Prof Educ Lvl | 170.5* 146.8* 164.0** 164.9** 279.9*** 157.1** Household 1 | 158.4* 158.5* 156.5* 148.9* -166.3 176.0** Household 4+ | 121.6 126.4* 124.3* 119.9* -88.50 148.0** Blue-Collar Occup. | 123.0* 88.64 117.4* 112.6* 139.0 111.6* Low Commute | -28.89 -29.32 -29.86 -32.49* 64.35** -30.75* Northeast | -10.61* -8.915* -9.016* -8.761* -2.108 -6.813* UA Population | 0.910 1.290 1.820* 2.317** -0.129 -0.472 Cntrl Pl. Dens. | 4.835*** 4.000*** 3.653*** 3.074*** 1.823 1.791* Log Govt. Fund | -0.809 -0.483 -0.608 -0.845 6.469*** 1.140 Log Gas Prices | 77.15 47.43 58.81* 92.00* 61.76 136.8*** UA Pop. /State Rd. | 0.119*** 0.122*** 0.130*** 0.139*** 0.127*** 0.0423***--------------------------------------------------------------------------------------------------------------------------------------------------------Omitted category: working age (25-65), h.s. education level, households of 2 and 3, white-collared occup., medium commute (15-44min.), midwest* - significant at 0.05 level** - significant at 0.01 level

OLS RegressionOLS Regression

Per Capita Transit Trips 2002 2003 2004 2005 2006 2007 | Coef. Coef. Coef. Coef. Coef. Coef. No. | 336 350 355 365 367 370 Pseudo R-sq. | 0.2797 0.2785 0.2875 0.2779 0.2769 0.2779 ------------------------------------|---------------------------------------------------------------------------------------------------------------- Old Age | 35.85 33.57*** 32.58 65.13* 60.55 90.33*** Pct. Poverty | 32.61 22.75*** 38.40** 31.81 21.03 8.080 Car Ownership | -14.95 -25.96*** -24.38*** -31.77* -16.58 -27.91* Prof Educ Lvl | 86.04** 125.1*** 113.9*** 110.9*** 160.0** 75.39** Household 1 | 48.43 19.25 53.74** 53.79 21.26 56.35* Blue-Collared | 18.66 23.06** 32.66* 10.06 34.43 -0.704 Low Commute | -13.12 -14.83*** -14.47*** -17.96* 7.609 -20.79** Northeast | -5.234* -4.256*** -5.056*** -5.258** -6.717* -2.458 West | -0.961 -0.987*** -1.029** -1.719* -1.711 -0.239 Population | 2.911*** 3.344*** 3.426*** 3.818*** 1.735* 4.501*** Cntrl Pl. Dens | 1.882*** 1.760*** 1.823*** 1.435*** 1.799* 1.111*** Log Home Value | -3.570 -5.530*** -5.296** -2.889 2.748 -2.685 Log Govt. Fund | 0.686 0.732*** 0.620** 0.352 2.355*** 0.670* Log Gas Price | 57.13** 31.88*** 43.10*** 61.83** 63.39 65.09*** UA Pop / State Rd. | 0.153*** 0.152*** 0.160*** 0.167*** 0.139*** 0.0429***--------------------------------------------------------------------------------------------------------------------------------------------------------Omitted category: working age (25-65), h.s. education level, households of 2 and 3, white-collared occup., medium commute (15-44min.), midwest* - significant at 0.05 level** - significant at 0.01 level

Median RegressionMedian Regression

Significant Levels* p<0.05, ** p<0.01, *** p<0.001

Mass Transit Ridership, 2000-2007 | Random Effects | Per Capita Trips Per Capita Miles No. | 2606 2606 -------------------------------------|------------------------------------------------------------------------------------- Old Age | 96.47* 196.5 Car Ownership | -55.96** -150.6 Prof Educ Level | 184.8*** 273.1 Household 1 | 39.57 1051.6** Household 4+ | 69.70 886.7** Northeast | -7.357* -11.30 UA Population | 2.071** 8.435 Cntrl Pl. Dens | 2.557*** 6.268 Log Govt. Fund | 1.671*** 7.011*** Log Gas Prices | 3.843*** 31.40*** City Age | -0.00113 -0.249* Urban Pop/ State Rd. | 0.0267*** 0.156** ---------------------------------------------------------------------------------------------------------------------------Omitted category: working age (25-65), h.s. education level, households of 2 and 3, white-collared occup., medium commute (15-44min.), midwest* - significant at 0.05 level** - significant at 0.01 level

Panel RegressionPanel Regression

FindingsFindingsMass Transit does not exist in a vacuum but responds to

External FactorsRidership correlates to Urban Area Characteristics and

Demographic CompositionKey Predictors: HH Size, Car Ownership, Educ. Level,

Commute Times, Pop., Density, Govt. Funds, Gas Prices, Public Road Miles

Policy ImplicationsPolicy Implications Transportation Planners collaborate with Urban

Planners, Local Businesses, and Public OfficialsInstall and revitalize transit systems by key variables

(pop., density, region) Incentivize specific groups (i.e. employment subsidies,

tax rebates)

AcknowledgmentsAcknowledgmentsUNC-CH: Jim Johnson, Saraswata Chaudhuri, Daniel

Rodriguez, Sociology Honors Seminar; Urban Institute: Kim Rueben, Brett Theodos, Lynette

RawlingsFord Foundation, UNC-CH Office of Undergraduate

Research, Dept. of City and Regional Planning