Traveler Response to Transportation System Changes Handbook, Third Edition: Chapter 15, Land Use and Site Design (2003) / Chapter Skim
Currently Skimming:
Pages 13-89
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 13... ...
15-13 effects of all urban form parameters may be substantial. The research utilizing San Francisco Bay Area survey data found elasticities for VMT per household of -0.31 for accessibility, and -0.10 each for land use balance and fine-grained mix, along with +0.56 for autos owned, through which small density effects were channeled.
|
From page 14... ...
15-14 aspects of an area including its suburbs, its people and their socio-economic characteristics, and its transportation features. After a brief look at density from the macro-perspective of metropolitan region totals, a behavioral level review follows.
|
From page 15... ...
15-15 Table 15-2 Population, Land Area, DVMT, and Road System Characteristics of the 15 Largest -- and 15 Selected Additional -- U.S. Urbanized Areas, 1998 State Location Federal-Aid Urbanized Area (Federal Highway Administration)
|
From page 16... ...
15-16 Figure 15-1 Daily vehicle miles of travel versus population density in the 65 largest U.S. urbanized areas – 1998 Source: Plot of data presented in FHWA (2000)
|
From page 17... ...
15-17 What these numbers illustrate is that, in general, places with higher densities do tend to have less reliance on auto travel. However, the anomalies cited in connection with Figure 15-1 provide ample evidence that there is more to the link between land use, urban form and travel behavior than can be explained by aggregate densities alone.
|
From page 18... ...
15-18 Table 15-3 Summary of Research Findings on Relationship of Density (as Prime Indicator) with Travel Behavior Study (Date)
|
From page 19... ...
15-19 Density Inclusive of Related Phenomena. A number of studies have shown a non-linear relationship between density and per-capita auto travel, with less per-capita vehicle travel at higher densities.
|
From page 20... ...
15-20 Table 15-4 Comparisons of VMT per Capita Rates at Different Gross Population Densities, San Francisco Bay Area Versus NPTS National Data Annual Vehicle Miles per Capita Density (per square mile) Comparison in Percent S.F.
|
From page 21... ...
15-21 Table 15-5 Average Daily Travel per Person in the United States by Population Density and Mode, 1990 NPTS Survey Daily Person Trips by Mode Density Range (Persons per Square Mile) Auto Bus Rail Taxi Walk/ Bike Other Total Daily Person Miles Daily VMT per Person 0 – 99 3.35 0.02 0.00 0.00 0.24 0.16 3.77 31.58 21.13 100 – 249 3.50 0.02 0.00 0.01 0.24 0.13 3.90 29.95 20.73 250 – 499 3.53 0.02 0.00 0.00 0.29 0.12 3.96 29.33 20.40 500 – 749 3.52 0.03 0.00 0.00 0.21 0.12 3.88 29.00 20.99 750 – 999 3.44 0.05 0.01 0.01 0.26 0.13 3.90 26.25 18.35 1,000 – 1,999 3.48 0.03 0.01 0.00 0.23 0.11 3.86 26.17 18.63 2,000 – 2,999 3.46 0.06 0.01 0.00 0.28 0.11 3.92 23.45 19.04 3,000 – 3,999 3.34 0.06 0.02 0.01 0.29 0.09 3.81 24.11 16.89 4,000 – 4,999 3.51 0.05 0.01 0.00 0.30 0.08 3.95 24.77 17.24 5,000 – 7,499 3.29 0.09 0.02 0.01 0.36 0.06 3.83 24.56 16.28 7,500 – 9,999 2.92 0.11 0.05 0.02 0.45 0.07 3.62 20.59 14.15 10,000 – 49,999 1.90 0.29 0.21 0.03 0.95 0.04 3.42 17.02 8.73 50,000 or more 0.59 0.42 0.61 0.16 1.55 0.07 3.40 12.55 2.31 Source: 1990 NPTS Survey, as presented in Dunphy and Fisher (1996)
|
From page 22... ...
15-22 Figure 15-2 Average daily VMT per person in the United States by population density, 1990 NPTS survey Figure 15-3 Average daily person trips per person in the United States by mode and density, 1990 NPTS survey Source: Both Figures – Table 15-5.
|
From page 23... ...
15-23 On the other hand, it was found that average household size varies very little (2.5 to 2.7 persons per household) except for the highest density communities, which have slightly smaller households (about 2.2 persons)
|
From page 24... ...
15-24 mation and Impacts" -- "Trip Making and VMT," are derived so as to be appropriate for use in additive fashion with similar elasticities pertaining to other land use/design characteristics. They seem to be largely isolated from related phenomena except, it may be surmised, from auto ownership effects.
|
From page 25... ...
15-25 Table 15-7 Summary of Research Findings on Relationship of Density and Other Indicators with Travel Behavior Study (Date) Process Key Findings Miller & Ibrahim (1998)
|
From page 26... ...
15-26 Distance from a CBD or major employment center is essentially a crude but handy measure of accessibility to jobs and related activities. Accessibility as a travel determinant is directly addressed in other studies examined in this section.
|
From page 27... ...
15-27 Portland, Oregon's 1994 activity-based household survey has provided data for wide ranging exploration of household and land use characteristics. One such research effort conducted statistical means tests to examine importance to household travel of various socioeconomic characteristics and land use factors, including unusual measures such as cellular phone ownership.
|
From page 28... ...
15-28 workplace accessibility to households exhibited even stronger corresponding relationships, there is a high likelihood that this particular variable was simply serving as a marker for persons employed in or around the CBD, and more likely to be users of transit. Table 15-8 Household Person Trip and Vehicle Travel Differentials Between Sociodemographic and Land Use Characteristic Groupings -- Portland, Oregon Means Test Variable Dividing Point of Means Test Groupings Mean Person Trips per Household (2 days, all modes)
|
From page 29... ...
15-29 Density, Accessibility, and Community Type. Six communities in Palm Beach County, Florida, ranging in residential density from 0.12 to 3.76 dwellings per acre (roughly 200 to 6,000 persons per square mile)
|
From page 30... ...
15-30 Density Rela ted to Transit Use The effectiveness of major investments in mass transit systems, or even various changes in transit service, depend critically on the ridership levels achieved by the service in relation to the amount of service provided and its capital and operating costs. Land use density has long been used as a major indicator of propensity for transit use and thus likely productivity in policy level assessments of transit service opportunities and practicality.
|
From page 31... ...
15-31 Table 15-10 Summary of Research Findings on Density and Transit Use Relationships Study (Date) Process Key Findings Newman & Kenworthy (1989)
|
From page 32... ...
15-32 Some of the research studies find higher densities required to sustain basic bus service than indicated by the guidelines identified in Table 15-9. This may reflect nothing more than confusion of basic bus service sustainability with having enough bus service to significantly affect mode choice, or a difference of opinion as to whether hourly bus service (as compared to half-hourly)
|
From page 33... ...
15-33 Studies for the Washington State Transportation Commission tested relationships at the census tract level between urban form, including density, and travel behavior. The 1989 Puget Sound longitudinal cohort study survey provided travel data, while demographic and land use information came from local and Census sources.
|
From page 34... ...
15-34 Table 15-11 Percentage Shifts in Mode in Response to a 10 Persons or Employees per Acre Density Increase -- Estimated Based on Puget Sound Travel Data Percentage Change in Use Purpose of Trip Density Increase Type and Location Trip End Location Walk Transit SOV Work Population at Origin n/a -- -- -5.0% Population at Destination n/a +2.5% -- -- Population at O and D Origin +7.0%*
|
From page 35... ...
15-35 effect of density on transit riding is much stronger than the effect of land use mix or urban design (Parsons Brinckerhoff et al., 1996a)
|
From page 36... ...
15-36 gradients that were fairly similar across systems in Washington, DC, California, and Canada. Ridership declined from 1 to 2 percent with every 100 foot increase in walk distance to stations, even though absolute values differed among cities.
|
From page 37... ...
15-37 to another mode and not walking directly to their destinations at the work end of the trip is actually quite small (Parsons Brinckerhoff et al., 1996b)
|
From page 38... ...
15-38 Table 15-13 Comparison of the Effects of an Increase in Densities on Mode of Access to BART, Metra, and CTA Rail Stations Percentage Point Change in Access Mode Share System Density Increase Walk Auto Transit BART One household/acre +1.7 -2.0 -0.7 One employee/acre +0.3 -0.9 -0.2 Metra One household/acre +2.2 -1.8 -- One employee/acre -- -- +0.5 CTA One household/acre +0.8 -0.2 -1.1 One employee/acre +2.2 -0.4 -2.1 Source: Parsons Brinckerhoff et al.
|
From page 39... ...
15-39 Diversity (Land Use Mix) Density, as the previous section illustrates, has historically been the central measure in studies of the relationship between land use and travel behavior.
|
From page 40... ...
15-40 Key jobs/housing ratio studies are summarized in Table 15-14.6 Selected studies are expanded upon within this section, or elsewhere in this chapter, where and as noted in the table. Note that the percentage of internal commuting (intra-zonal, intra-district or intra-city)
|
From page 41... ...
15-41 Table 15-14 Summary of Research Findings on Jobs/Housing Balance and Work Commute Travel Behavior Study (Date) Process Key Findings Frank & Pivo (1994b)
|
From page 42... ...
15-42 Two studies with at least limited consideration of income factors, speculative-only in the first instance, are expanded upon here. Trends in jobs-housing balance and commuting patterns between 1980 and 1990 in the 23 largest San Francisco Bay Area cities received study by Cervero.
|
From page 43... ...
15-43 Angeles. Yet, because of walking and transit use, New Yorkers generate 30 percent less in annual [per unit of measure]
|
From page 44... ...
15-44 Figure 15-4 Percentage of residents who work in city/place of residence as a function of jobs/housing balance, Washington State Note: Once adjusted jobs/housing balances exceed 1.0, the increase in percentages of residents working within their own city/community (illustrated in the figure) starts to be overshadowed by the increase in percentages of workers in-commuting from outside the city/community (a phenomenon not illustrated in the figure)
|
From page 45... ...
15-45 In contrast to density, land use balance became more common over the period in the various districts of Central Puget Sound. To assess balance, an adjusted jobs-housing balance was computed by dividing jobs by households for each place, and then dividing that by the mean number of jobs per household in the whole metropolitan area.
|
From page 46... ...
15-46 The same Job Balance formula was applied to eleven "new" communities around the United States. The very highest internal capture rates thus estimated, employing 1990 Census data, were on the order of 31 to 37 percent.
|
From page 47... ...
15-47 Table 15-16 Summary of Research Findings on Accessibility, Entropy and Other Measures, and Travel Behavior Study (Date) Process Key Findings Frank & Pivo (1994a and b)
|
From page 48... ...
15-48 Table 15-16 Summary of Research Findings on Accessibility, Entropy and Other Measures, and Travel Behavior, Continued Study (Date) Process Key Findings Steiner (1998)
|
From page 49... ...
15-49 Table 15-17 Correlation Between Urban Form Variables and Mode Choice Work Trips Mode Choice Variables (% Share) Employment Density Population Density Mixing of Uses SOV -0.26 -- -0.13 Carpool -- -- 0.18 Transit 0.59 0.19 0.15 Walk 0.43 0.34 0.21 Shopping Trips SOV -0.15 -- -- Carpool -- -- 0.16 Transit 0.44 0.16 -- Walk 0.24 0.31 -- Sources: Frank and Pivo (1994a)
|
From page 50... ...
15-50 Accessibility and Land Use Mix. Also introduced in the "Density" section, under "Density and Other Indicators at the Behavioral Level" -- "Density as a Proxy," was the 1996 thesis research by Kockelman.
|
From page 51... ...
15-51 describing mix did not have significance in predicting mode choice, however, including walk/bike use. Table 15-18 Elasticity Estimates from Model Results, Kockelman Thesis a With respect to VMT per Household NWHB VMT/HH Auto Ownership PV Mode Choice a Walk/Bike Choice a Household size (age 5+)
|
From page 52... ...
15-52 walk omitting the El Cerrito site with its large intervening parking lot. Rates of walking were much higher among residents living within one mile of the shopping district: between 24 and 65 percent at all six shopping areas.
|
From page 53... ...
15-53 Table 15-20 Percentage of Respondents by Distance of Residence from Six OaklandBerkeley, California, "Traditional" Shopping Areas "Residents" "Non-Residents" "Traditional" Shopping Area Within 1/2 mile Between 1/2 & 1 mile Total Within 1 mile Between 1 & 5 miles More than 5 miles Total Beyond 1 mile Rockridge-Market Hall 24% 14% 37% 32% 31% 63% Rockridge-Alcatraz 40 21 62 25 13 38 Elmwood 33 18 51 29 20 49 El Cerrito Plaza 12 27 39 52 9 61 Hopkins 32 20 52 33 15 48 Kensington 58 18 76 19 5 24 All Areas 32% 20% 52% 32% 16% 48% Source: Steiner (1998) Table 15-21 Vehicle Trip Generation and Parking Rates for Six Oakland-Berkeley, California, Shopping Areas Compared to ITE Trip Rates and Two Parking Standards Average Hourly Vehicle Trip Ends Parking Used/Recommended Local Rates ITE-Based Rates Local Data Standard "Traditional" Shopping Area Weekdays Saturdays Weekdays Saturdays Weekdays Saturdays New Urbanist ULI Rockridge-Market Hall 6.42 12.71 6.41 6.06 263 357 195 261 Rockridge-Alcatraz 5.22 6.96 6.12 5.78 127 184 221 369 Elmwood 5.02 7.19 5.45 5.15 208 313 311 415 El Cerrito Plaza 1.46 1.76 3.43 3.02 182 286 1,301 1,917 Hopkins 8.55 14.82 8.31 7.85 77 139 90 120 Kensington 2.08 2.64 9.57 9.05 4 6 59 79 Notes: Vehicle trip end rates are expressed as vehicle trip ends per 1,000 square feet of retail space.
|
From page 54... ...
15-54 Parking generation was also compared with standard sources, as shown in the second half of Table 15-21. Here it was found that the parking demand at the highly successful RockridgeMarket Hall shopping area exceeded both what New Urbanist minimums (per Calthorpe)
|
From page 55... ...
15-55 Table 15-22 Summary of Research Findings on Land Use Mix and Transit Use Study (Date) Process Key Findings Hooper (1989)
|
From page 56... ...
15-56 The quantitative results obtained in those cases where the first four listed studies did identify land use mix effects are generally consistent with findings from a TCRP Project H-1 analysis of travel behavior of over 15,000 households surveyed in 11 metropolitan areas in the 1985 American Housing Survey. The findings suggest that both land use mix and residential densities are linked with mode choice decisions, as illustrated in Figures 15-5 and 15-6.
|
From page 57... ...
15-57 Figure 15-5 Probability of commuting by transit as a function of auto ownership, for four land use scenarios Figure 15-6 Probability of commuting by walking or bicycling as a function of auto ownership, for four land use scenarios Note: Both Figures – Based on modeling of survey results from the 11 metropolitan areas (MSAs or CMSAs) of Boston–Lawrence–Lowell, Dallas, Detroit, Los Angeles–Long Beach, Fort Worth– Arlington, Minneapolis–St.
|
From page 58... ...
15-58 These high walk choice elasticities reinforce the importance of land use mix to the use of nonmotorized modes, indicating a strong positive relationship between walk access choice and presence of mixed land use, paired with a strong negative relationship between auto access choice and greater mix. The finding is sufficiently strong to withstand uncertainties introduced by the research model having been structured to estimate home-end and nonhome-end access/egress jointly (in total)
|
From page 59... ...
15-59 characteristics of suburban employment centers, the setting for the late 20th Century mass movement of jobs to suburban areas. Other research has looked at the value of traditional transportation networks with grids and small blocks in contributing to shaping mode choice, trip length, VMT, and travel speed.
|
From page 60... ...
15-60 Table 15-23 Summary of Research Findings on Site Design of Suburban Activity Centers and Travel Behavior Study (Date) Process Key Findings Hooper (1989)
|
From page 61... ...
15-61 Table 15-24 Employment and Office Commute Mode Characteristics at Six Large-Scale Suburban Activity Centers Employees (thousands) Office Employee Commute Mode Suburban Activity Center Office Retail Total Employees per Gross Acre a Drive Alone Auto Pass.
|
From page 62... ...
15-62 Bellevue also exhibited higher mid-day office-worker use of non-auto modes, with about 1/4 of midday office-worker trips in Bellevue made by walking. An average of 6 percent of such trips were made on foot at the other five SACs.
|
From page 63... ...
15-63 • Vehicle Occupancy: Scale, level of mixing, and parking supply were found to affect ridesharing. – A 1 million square foot building, for example, averaged 0.8 more passengers per work trip than a building half that size.
|
From page 64... ...
15-64 4. Moderate-Size MXDs: Resembling large MXDs, but with far less acreage -- typically less dense but a well-defined, architecturally-integrated core.
|
From page 65... ...
15-65 Table 15-27 Suburban Employment Center Land Use and Commute Characteristics Land Use Characteristic a (density/mix/design) Office Parks Office Centers Large MXDs Medium MXDs SubCities Large Corridors Number of Sites Studied 10 8 14 8 10 7 Acreage (thousands)
|
From page 66... ...
15-66 • The share of work trips made by walking averaged on the order of 1 percent overall, compared to 4 percent nationally. It was highest in Sub-Cities (1.4 percent)
|
From page 67... ...
15-67 As Table 15-28 illustrates, sites with poor or fair access to commercial/retail services averaged per-employee vehicle trip rates lower by 5.3 and 8.3 percent compared to ambient rates, respectively, while sites with good access averaged rates lower by 21.5 percent. This analysis does not suggest that the availability or lack of services is the sole reason for the differences in trip rates, but rather that TDM or other transportation alternatives are more likely to succeed in areas where employees do not remain auto dependent once at the work site.
|
From page 68... ...
15-68 had an aesthetic urban setting, a 4.1 percentage point higher transit mode share in the presence of TDM financial incentives, was similar (but presumably not additive)
|
From page 69... ...
15-69 Table 15-30 Summary of Research Findings on Design of Transportation Networks and Travel Behavior Study (Date) Process Key Findings Kulash, et al.
|
From page 70... ...
15-70 A subsequent study by McNally and Ryan also used modeling to explore potential neotraditional network transportation benefits, but with some added refinements. All categories of travel were included in the analysis, and traffic flow conditions were assessed with both link volume/capacity and intersection level of service calculations.
|
From page 71... ...
15-71 subregional perspective (McNally, 1995/96)
|
From page 72... ...
15-72 Table 15-32 Summary of Research Findings on Design of Neighborhoods (Traditional Versus Conventional Suburban) and Travel Behavior Study (Date)
|
From page 73... ...
15-73 Table 15-33 Mode Choices and Average Daily Person Trips per Household in Certain San Francisco Bay Area Traditional and Suburban Neighborhoods, 1980 Mode of Travel (Percent and Trip Totals by Mode) Trip Type Community Type Auto Driver Auto Passenger Transit Bicycle Walk Other Total Traditional 73% 8% 11% 2% 4% 2% 100% HomeBased Work Suburban 83% 7% 4% 2% 3% 1% 100% Traditional 51 21 7 6 14 1 100 HomeBased NonWork Suburban 60 23 3 3 10 1 100 Traditional 70 7 5 2 15 1 100 Work-Based Other Suburban 77 11 2 1 8 2 101 Traditional 58 19 4 2 17 0 100 Non-HomeBased Suburban 66 25 1 1 8 0 101 Traditional 61% 16% 7% 4% 12% 1% 101% All Trips Combined Suburban 68% 18% 3% 2% 8% 1% 100% Traditional 5.3 1.41 0.62 0.35 1.06 0.09 8.83 Trip Totals (Trips)
|
From page 74... ...
15-74 each block of variables introduced into the models added statistically significant explanatory power. Neighborhood descriptors tested were as follows: • Study Area Indicators: 1 through 5 to identify each neighborhood • Macro Area Descriptors: Yes/no for BART access; mixed use, and high density (each)
|
From page 75... ...
15-75 Table 15-34 Significant Associations of Neighborhood Descriptors with Trip Rates and Modal Shares in Five-Neighborhood San Francisco Bay Area Study Travel Demand Variable Significant Negative Factors Significant Positive Factors Number Person Trips (person trip generation) • BART rail transit access a • Exclusive parking for residence • North San Francisco location b • High density • Backyard Number Transit Trips (transit trip generation)
|
From page 76... ...
15-76 trips, transit share, and bike/walk share, and positively related to auto shares (Kitamura, Mokhtarian and Laidet, 1994) .8 Traditional Neighborhoods Versus Hierarchical Planned Unit Developments.
|
From page 77... ...
15-77 Table 15-35 Orange County, California, 1991 Household Characteristics in Neighborhoods of Different Types Type of Neighborhood Household or Individual Characteristic TND Hybrid PUD All Types Single Family Dwelling (Percent) 39% 61% 67% 59% Household Size (Mean)
|
From page 78... ...
15-78 Table 15-36 Orange County, California, 1991 Trip Rates and Mode Shares in Neighborhoods of Different Types, Stratified by Income Mean Daily Trips per Household / Percent Mode Shares Travel Parameter Income TND Hybrid PUD All Types Low 6.4 6.5 7.2 6.5 Medium 8.8 9.6 10.7 9.9 High 10.8 14.6 12.3 12.5 Mean Daily Total Trips per Household ALL 8.2 8.9 10.9 9.6 Low 5.1 5.7 6.6 5.6 Medium 8.0 8.6 9.7 8.8 High 10.2 12.8 11.3 11.6 Mean Daily Auto Trips per Household ALL 7.0 8.1 9.8 8.5 Low 80 87 91 86 Medium 91 90 91 90 High 94 88 92 92 Auto Mode Share (Percent) ALL 86 87 91 89 Low 6 3 0 3 Medium 2 3 2 2 High 1 1 1 1 Transit Mode Share (Percent)
|
From page 79... ...
15-79 work purpose travel, 51 percent of Rockridge commuters drove alone compared to 69 percent in Lafayette. A slightly higher percentage carpooled in Rockridge (12 versus 10 percent)
|
From page 80... ...
15-80 Statistics stratified by non-work activity that further highlight the travel differences enabled by the Rockridge environment include (Cervero and Radisch, 1995) : • 19 percent of shopping trips made by non-auto versus 2 percent in Lafayette.
|
From page 81... ...
15-81 • Wallingford: A medium-sized (0.75 by 1.25 miles) community with a diverse land use, located 4 miles north of downtown Seattle, adjacent to I-5 and the University of Washington, also centered on a main shopping area and featuring a grid street pattern.
|
From page 82... ...
15-82 Table 15-39 Summary of Seattle Community and Broader Area Household and Weekday Travel Characteristics Queen Anne Wallingford North Seattle a Kirkland Inner Ring Outer Ring Household Characteristics Household (HH) size 2.2 2.1 1.9 2.0 2.5 2.7 Employees per HH 1.4 1.3 1.2 1.0 1.4 1.4 Vehicles per HH 1.7 1.6 1.8 1.9 2.1 2.2 Median age persons over 15 39 37 37 47 35 37 Percent income over $35,000 67% 56% 41% 61% 56% 55% Gross density, HH per acre 7.6 7.2 5.4 3.1 1.2 0.2 Travel Distance Characteristics Average daily mileage per person (over 15 years of age)
|
From page 83... ...
15-83 On the other hand, linkage between distance and walking appeared to be highly related to community structure. Table 15-40 provides a comparison of the percentage of trip stops (trip ends -- presumably opportunity sites)
|
From page 84... ...
15-84 characteristics of the built environment that are conducive to transit use. Beyond density and mix of development, essential land use ingredients for full-featured TOD communities, transit supportive design includes such elements as: • Connectivity of streets in a manner supportive of both bus routing without circuitry and easy rider access to stops and stations.
|
From page 85... ...
15-85 Table 15-41 Summary of Findings on Transit Supportive Design and Travel Behavior Study (Date) Process Key Findings Parsons Brinckerhoff et al.
|
From page 86... ...
15-86 Table 15-42 Transit Shares at Worksites with Both TDM Programs and the Indicated Alternative Land Use Characteristics Independent Variables Collapsed into the Principal Characteristic Principal Land Use or Site Design Characteristic Percent Transit with Land Use/Design Characteristic Percent Transit Without Land Use/Design Characteristic Percentage Point Difference Offices, residential, retail, personal services, parks (within 1/4 mile of site) Substantial Land Use Mix 6.4% 2.9% +3.5% Presence of 4 or more services, frequency of certain services, sidewalks, traffic, transit stops Accessibility to Services 6.3% 3.4% +3.3% [sic]
|
From page 87... ...
15-87 streets) , street continuity (directness versus cul-de-sacs, long blocks, and circuitry)
|
From page 88... ...
15-88 Table 15-43 Sensitivity Test Results of Portland, Oregon LUTRAQ Land Use, Design and Comparison Variables Impact on Daily Household Change in Explanatory Variable VMT Vehicle Trips Land Use and Design Variables Increase in PEF by one unit out of a possible increase of eight units -0.7 miles -- Increase in PEF from pedestrian-hostile to almost average (+3 units) -- -0.4 trips Increase in PEF from almost average to fairly good (+3 units)
|
From page 89... ...
15-89 It would appear that the San Francisco PEFs will prove as important in explaining choice of travel mode as the Portland area LUTRAQ PEFs, but lacking published sensitivity tests and given the newness of the model structures, it is premature to assign quantitative assessments of absolute importance here. Instead, Table 15-44 has been developed by examining the range of the operative travel time equivalencies of the PEFs, and dividing them into three equal ranges of relative importance, holding aside the school tour model.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.