Smart growth and transit-oriented development proponents advocate increasing the density of new land development and infill redevelopment. This is partly in order to reduce auto use by reducing distances between trip origins and destinations, creating a more enjoyable walking environment, slowing down road travel, and increasing the market for transit. But research investigating how development density influences household travel has typically been inadequate to account for this complex set of hypotheses: it has used theoretically unjustified measures, has not accounted for spatial scale very well, and has not investigated potentially important combinations of measures.
Technological determinism has become a kind of religion for many people since it appears to offer solutions for societal problems as never before in history. Transport is one of the fascinating technology branches developed during the last 200 years. Effortless movement over long distances has become possible for car users as long as cheap fossil energy is available. However, the effect of fast transport on urban structures and society was not taken into account when developing these technical means. Technologists and economists have used indicators for expected benefits of these fast transport modes without taking into account the real system effects on society and urban structures. Plausible assumptions and hopes instead of scientific understanding of the complex system are used in practice. In contradiction to widely held beliefs of transportation planners, there is actually no growth of mobility if counted in number of trips per person per day, no time saving by increasing…
The objective of the study is to collect and add to the existing parking and trip generation data available on transit oriented developments. Students from Portland State University’s ITE Student Chapter collected data to determine residential parking demand and trip generation by mode split at three downtown residential housing developments in a transit oriented development. The housing developments selected for the study included three privately owned condominiums with a minimum of 100 dwelling units and a private residential parking garage.
In order to show the ridership benefits of TOD, we examined the best empirical information available for adjusting vehicle trip generation rates and estimating transit ridership. Fortunately, a fair amount of empirical evidence has been gathered in California over the past decade on TOD’s ridership impacts. The approach taken parallels somewhat that employed for the Air Resources Board’s URBEMIS model that aims to evaluate the potential emission-reduction benefits of smart-growth strategies. The URBEMIS model provides a range of “adjustment factors” for reducing estimated vehicle trip volumes by specific percentages based on characteristics of built environments – including the 3Ds of density, diversity, and design. We propose that the evaluative tool, like URBEMIS, will begin with standard ITE vehicle trip generation rates to estimate the potential reductions in vehicle use a TOD offers compared to a conventional suburban development (the basis of the most use ITE trip…
Which land-use sirategy yields greater reductions in vehicular travel: improving the proximity of jobs to housing or bringing retail and consumer services closer to residential areas? We probe this question by examining the degree to which job accessibility is associated with reduced work travel and how closely retail and service accessibility is correlated with miles and hours logged getting to shopping destinations. Based on data from the San Francisco Bay Area, we find that jobs-housing balance reduces travel more, by a substantial margin. The article concludes by discussing policy measures that have been introduced in California bring housing, workplaces, and retail centers closer together.
The transit rider or the customer generally has one purpose in mind - getting from here to there on transit with the greatest ease and convenience possible. The customer’s ease of transferring from one transit system to another is “connectivity.” It is important to understand that connectivity is measured from the perspective of the customer. While the transit operators, the funding agencies, and others may have their views and measures of connectivity, the customer’s perception is the standard against which service quality should be determined.
A major goal of urban design, especially in centers, is to reduce automobile dependence in order to address issues of viability and sustainability. Long-term data from cities around the world appear to show that there is a fundamental threshold of urban intensity (residents and jobs) of around 35 per hectare1 where automobile dependence is significantly reduced. This article seeks to determine a theoretical base for what the data show. It suggests that below the threshold intensity of urban activity, the physical constraints of distance and time enforce car use as the norm. The basis of these physical constraints is outlined and the link between density and access to services that provide amenity is established, including the service levels of public transport. A design technique for viability of centers is suggested as well as how a city can restructure itself to overcome automobile dependence.
In the past ten years, integrated land use and transportation modeling has received considerable attention in the scholarly literature. This academic interest is slowly yielding practical applications. Many metropolitan planning organizations (MPOs) and state departments of transportation are beginning to implement these types of models for the first time. While many improvements have been made to these models, and the value of these improvements should not be understated, much work still remains. One of the most challenging problems in land use modeling is how floorspace (buildings) is built and occupied. The purpose of this paper is twofold: first, to draw attention to insufficiencies in the representation of floorspace developer behavior—particularly as it applies to large, urban-edge projects—within current integrated land use and transportation models and, second, to determine the necessity of explicitly accounting for such projects within these models.
Decentralized employment growth has cut into transit ridership across the United States. In California, about 20 percent of those working in office buildings near rail stations regularly commute by transit, nearly three times transit’s modal share among those working away from rail stations. Mode choice models reveal that office workers are most likely to rail-commute if frequent feeder bus services are available, their employers help cover the cost of taking transit, and parking is in short supply. Factors like trip-chaining and the absence of restaurants and retail shops near suburban offices, however, deter transit-commuting. Policy-makers can promote transit-commuting to offices near rail stops by flexing parking standards, introducing high-quality feeder buses, and initiating workplace incentives such as deeply discounted transit passes. While housing has generally been the focus of transit-oriented development, unless the other end of the commute trip—the workplace—is also…
This paper examines demographic, economic and market trends that affect travel demand, and their implications for transport planning. Motorized mobility grew tremendously during the Twentieth Century due to favorable demographic and economic conditions. But many factors that caused this growth, such as declining vehicle operating costs and increased vehicle travel speeds, are unlikely to continue. Per capita vehicle ownership and mileage have peaked in the U.S., while demand for alternatives such as walking, cycling, public transit and telework is increasing. This indicates that future transport demand will be increasingly diverse. Transport planning can reflect these shifts by increasing support for alternative modes. Although this paper investigates trends in the U.S. and other wealthy countries, the analysis has important implications for developing countries.