Keywords: car sharing, transport planning

Keywords: land use transport link, transport planning, transit-oriented development

Claims that roadway investments spur new travel, known as induced demand, and thus fail to relieve traffic congestion have thwarted road development in the United States. Past studies point to a significant induced demand effect. This research employs a path model to causally sort out the links between freeway investments and traffic increases, using data for 24 California freeway projects across 15 years. Traffic increases are explained in terms of both faster travel speeds and land use shifts that occur in response to adding freeway lanes. While the path model confirms the presence of induced travel in both the short and longer run, estimated elasticities are lower than those of earlier studies. This research also reveals significant “induced growth” and “induced investment” effects-real estate development gravitates to improved freeways, and traffic increases spawn road investments over time. Travel-forecasting models are needed that account for these dynamics.

A much more sophisticated methodology to help untangle a complicated problem. The model suggests that it may be possible to build out of congestion without road pricing, although the author speculates that the ultimate urban form may look something like Houston. An interesting side note is the role of density, which exerts a strong influence on the level of induced demand. Unfortunately, since the dataset is from Southern California where truly high densities are rare, the model cannot say too much about roadway expansion in dense areas.

Keywords: transport planning, induced travel, urban form, land use transport link

Some claim that cardependent cities contribute to obesity by discouraging walking and bicycling. In this article, we use household activity data from the San Francisco region to study the links between urban environments and nonmotorized travel.

We used factor analysis to represent the urban design and land-use diversity dimensions of built environments. Combining factor scores with control variables, like steep terrain, that gauge impediments to walking and bicycling, we estimated discrete-choice models. Builtenvironment factors exerted far weaker, although not inconsequential, influences on walking and bicycling than control variables.

Stronger evidence on the importance of urban landscapes in shaping foot and bicycle travel is needed if the urban planning and public health professions are to forge an effective alliance against cardependent sprawl.

A good study looking at the factors influencing cycling and walking. The perspective is Cervero's usual framework, the three Ds: density, diversity and design. All three are found to have significant influences on bicycle usage, with the residential end being slightly more important. Of the urban form variables, the presence of neighbourhood retail is found to be the strongest predictor of walking.

From an evaluation standpoint, I wish these authors would standardize/normalize the coefficients of their models! After limiting to statistically significant variables, normalization would allow me to compare the relative influence of each variable on bicycle usage. It would also be extremely useful to include the mean and standard deviation of all input variables, to allow some rough comparisons to other study areas. If the input data has low variance (e.g., a uniformly low-density suburb), meaningful patterns could be missed.

Finally, the bicycle model seems pretty shoddy-the rho-squared value is only 0.13! Since it only considers factors at origin and destination, I imagine it's missing a massive amount of valuable data, like the topography, safety and quality of the route itself.

Keywords: active transportation, pedestrian planning, bicycle planning, urban form, bicycle modelling

Keywords: urban form, urban planning, transport planning

Keywords: urban form, land use transport link

Keywords: induced travel, transport planning, land use transport link

Keywords: transport planning, transit, urban planning

Keywords: urban planning, transport planning, land use transport link

Keywords: land use transport link, transport planning

detailed annotation

Keywords: transit, urban planning, transport planning, canada, land use transport link, urban form, transit-oriented development

A good, balanced paper.

A few comments on the models: the first model does not account for spatial autocorrelation, which may be an issue. The finding that station location within a highway median, incentive zoning, and restrictive zoning were not statistically correlated with building activity around stations is quite interesting.

Keywords: transit, urban planning, transport planning, land use transport link

The built environment is thought to influence travel demand along three principal dimensions - density, diversity, and design. This paper tests this proposition by examining how the “3Ds” affect trip rates and mode choice of residents in the San Francisco Bay Area. Using 1990 travel diary data and land-use records obtained from the U.S. census, regional inventories, and field surveys, models are estimated that relate features of the built environment to variations in vehicle miles traveled per household and mode choice, mainly for non-work trips. Factor analysis is used to linearly combine variables in the density and design dimensions of the built environment. The research finds that density, land-use diversity, and pedestrian-oriented designs generally reduce trip rates and encourage non-auto travel in statistically significant ways, though their influences appear to be fairly marginal. Elasticities between variables and factors that capture the 3Ds and various measures of travel demand are generally in the .06 to .18 range, expressed in absolute terms. Compact development was found to exert the strongest influence on personal business trips. Within-neighborhood retail shops, on the other hand, was most strongly associated with mode choice for work trips. And while a factor capturing “walking quality” was only moderately related to mode choice for non-work trips, those living in neighborhoods with grid-iron street designs and restricted commercial parking were nonetheless found to average significantly less vehicle miles of travel and rely less on single-occupant vehicles for non-work trips. Overall, this research shows that the elasticities between each dimension of the built environment and travel demand are modest to moderate, though certainly not inconsequential. Thus is supports the contention of new urbanists and others that creating more compact, diverse, and pedestrian-oriented neighborhoods, in combination, can meaningfully influence how Americans travel.

A solid study, and a useful decomposition of urban form. By the time I got around to reading it, I'd seen several similar papers (like Cervero and Duncan's later followup), so the conclusion was not surprising.

Keywords: urban planning, transport planning, urban form, land use transport link

Keywords: transit, urban planning, transport planning

Keywords: transit, transport planning

Keywords: urban form, transport planning, urban planning

Keywords: transit, transport planning, urban planning

This paper is the best I've read on the jobs-housing issue, with a careful distinction between balance and containment, an examination of balance-with-mismatch, and a more careful analysis of the impacts on VMT and mode split.

One finding that interested me: balance was not correlated with a substantial change in VMT, but containment was (and was also correlated with higher levels of walking). Another interesting conclusion: imbalance is a planning failure, not a market failure, since it usually happens in jobs-surplus areas where residents apply political pressure (read: NIMBYism) to fight any market-driven changes to the residential stock.

I liked the description of jobs-housing balance as the potential for self-containment. I see the actual level of self-containment to be a function of two variables: jobs-housing balance, and travel times. Jobs-housing balance allows a city to easily respond to congestion or degraded travel times, by giving workers the option of moving closer to their jobs.

Keywords: urban planning, land use transport link, urban form

Keywords: transit, transport planning, urban planning, urban form, land use transport link

Past research suggests that mixed land-uses encourage non-auto commuting; however, the evidence remains sketchy. This paper explores this question by investigating how the presence of retail activities in neighborhoods influences the commuting choices of residents using data from the 1985 American Housing Survey. Having grocery stores and other consumer services within 300 feet of one's residence is found to encourage commuting by mass transit, walking and bicycling, controlling for such factors as residential densities and vehicle ownership levels. When retail shops are beyond 300 feet yet within 1 mile of residences, however, they tend to encourage auto-commuting, ostensibly because of the ability to efficiently link work and shop trips by car. The presence of nearby commercial land-uses is also associated with relatively low vehicle ownership rates and short commuting distances among residents of a mixed-use neighborhood. Overall, residential densities exerted a stronger influence on commuting mode choices than levels of land-use mixture, except for walking and bicycle commutes. For non-motorized commuting, the presence or absence of neighborhood shops is a better predictor of mode choice than residential densities.

Keywords: transport planning, urban planning, land use transport link, urban form

Keywords: urban form, transport planning, urban planning, urban design

Apparently fairly important - shows benefits of traditional neighbourhood design.

Keywords: pedestrian planning, urban planning, urban form, urban design, land use transport link

Keywords: transit, transport planning, urban planning

I found their description of Houston interesting. I'd heard a lot about Houston's laissez-faire no-zoning policies, but I'd never read anything about the details. It sounds like they still suffer from the same social exclusion effects as many U.S. residential areas, but they use deed restrictions to enforce the exclusion instead of zoning laws. The authors give a surprisingly positive review to the HOV system overall, quite different from what I'd heard about HOV lanes in the present day context. Overall, Houston sounds like a depressing place to live or work. The complete rejection of land use control and the overwhelming dominance of the automobile turn me off. The Washington, D.C. case study wasn't very interesting to me, focusing mainly on transit-oriented development plans. The Portland section was slightly more interesting, again focusing on how land use goals are achieved by the agencies involved. The Vancouver section was mostly familiar, but did contain some interesting details that were new to me. There are some strange comments, though-they claim that the “European and Asian heritage of the region has also made the Vancouver community more accepting of transit” and characterise Vancouver as very unique within Canada. That's total rubbish-Canadian cities generally have an accepting attitude towards transit and a diverse cultural mix, and American cities have as much of a “European heritage” as Canadian ones. Sure, Vancouver is younger-but that should put it in the same boat as other young west coast cities, like Seattle. Some of their discussion regarding the history of SkyTrain is interesting, however, especially the idea that the Expo line was deliberately run through empty industrial areas to reduce NIMBY resistance and to allow new, denser transit-oriented development. They also note that TransLink does not own the land under the SkyTrain, allowing existing owners to make good use of the land, building towers around the tracks, etc. This is vastly better than the freeway model, where the land underneath and nearby is just dead space. Interestingly, they note that both Canadian and American government agencies put out a Request For Proposals (RFP) for a low-cost site, but only Canadian agencies can make location a requirement-i.e., requiring a site on the SkyTrain line.

I'm a bit dubious about their Ottawa section. They speak in glowing terms about many of the details of the system, and it doesn't always jibe with my experience when I lived there. Granted, I lived in a lousy area (far from the transitway) with a poor commute pattern. But there was a huge chunk of underserviced city where I lived, and I did see how the policies were working out on the ground. However, the policies sound like good ideas, at the least. They started with a bizarre statistic to make Ottawa look good: “Passengers per route mile in the first year,” a statistic biased towards bus systems, before development associated with a fixed rail system is completed. It's nice that (like Vancouver) they officially prioritise transit over road improvements, and that they consider it an official service. Their policy of building early in suburban areas is also an excellent idea, as is the policy of forcing regional shopping centres to be within 5 minutes walk of a transit station. (I have to wonder if that applies to big box zones, though-they were certainly abundant in the Ottawa area when I lived there. The abhorrent South Keys development all happened under these policies.) The Transitway design is clever, since they left enough room to allow later conversion to a rail system. One telling quote: “These services are adapted to, and as a result, help reinforce, the region's suburban landscape. In Ottawa-Carleton, it is accepted that low-density living environments are preferred by most residents, and that transit programs should in no way seek to alter this settlement pattern, but rather to serve it.” To be fair, that pattern may be changing now-the condo boom has definitely hit Ottawa. I suspect some of these sentences reflect the suburban American audience of this report. Ottawa also has taken a serious attitude towards directing job growth to transit corridors, in a manner similar to the Dutch ABC system. They also route buses through subdivision collector roads instead of arterial streets, to make for easier pedestrian access and avoiding the fight to access buses on arterials. (This may explain some of my confusion with the bus system, since I was more accustomed to the Toronto approach. It may also explain why buses were often poor choices for reaching retail areas, usually located on the arterials. It sounds like that was mostly political bad luck, though, not design-developers have insisted on siting commercial development on the arterials, not the planners' first choice.) Their reduction in downtown parking is admirable, with a 15% reduction from 1975 to 1984, a period of regression for most cities. They don't really comment much on the fact that many Transitway stations are built in parkland with no adjacent development, but they do note that future stations are being built in advance of development, with an aim to integrate better with mixed-use neighbourhoods. They claim pessimistically that the high-density transit-oriented residential demand had reached saturation point (!!) in Ottawa by 1993. At the end of the day, they've had difficulty achieving their goals, with regional employment share near transit stations remaining fairly static from 1986-1991. But they're still far ahead of most of North America.

Keywords: transit, transport planning, urban planning, canada, land use transport link

Keywords: pedestrian planning, urban planning, urban form, urban design, land use transport link

Keywords: transit, urban planning, rail, urban form

Keywords: transit, urban planning, land use transport link, transport planning

Keywords: urban planning, transit, land use transport link

Keywords: transit, land use transport link, transport planning, urban planning, urban form

Keywords: transit, transport planning

Keywords: transport planning, urban planning

Keywords: urban planning, transit-oriented development

Keywords: transit, urban form, land use transport link, urban planning, transport planning

Keywords: urban planning, transit

Keywords: transport planning, urban planning, land use transport link

Keywords: urban planning, transport planning

Keywords: urban planning, transport planning, land use transport link

Keywords: urban form, urban planning, transport planning, land use transport link

Keywords: transit, urban planning, transport planning

Keywords: transit, finance, equity

Keywords: transit, finance, equity

Keywords: urban planning, transport planning, land use transport link, urban form

Keywords: urban planning, urban form, urban design

Keywords: transport planning, urban planning, land use transport link

Keywords: urban planning, transport planning, urban form, land use transport link

Keywords: transport planning, urban planning, canada, transit

Keywords: transport planning, urban planning

Keywords: transit, transport planning

Keywords: canada, transit, transport planning

Keywords: urban planning, transit, transport planning, rail, land use transport link

Keywords: equity, transit, finance

Keywords: transit