In the United States, we often have expensive housing for people and free parking for cars. Parking reforms therefore are a promising way to reduce the price of housing and, in some cases, increase the supply of housing. Backyard cottages and converted garages are a unique form of housing that can be adapted over a lifetime, increase the supply of affordable housing, and make homeownership more feasible by providing rental income to homeowners. In this paper we propose two small changes in cities’ zoning for parking that can increase the supply of housing right in our own back yards: 1) relax off-street parking requirements for backyard cottages; and 2) create neighborhood parking permit districts. In this way, relatively minor policy changes could make a big difference in allowing homeowners to convert garages for cars into housing for people without creating any overspill of parked cars onto the streets. These simple parking reforms will help adapt the urban landscape to a changing future.

Parking is a critical element in sustainable transportation policies as it directly affects mode choice, land use, street safety, etc. Still, it does not receive as much attention as it should in the research agenda compared to other topics. One of the reasons for the lack of research and quantitative assessment is the complexity, time and burden associated with the gathering, processing and analysis of data on parking supply and demand. Actually, parking studies tend to be often limited to small areas and focused on specific issues. This research proposes a method to derive zonal parking use from the systematic processing of car trips observed from household travel surveys. Three consecutive large-scale surveys from the Montreal area are processed to illustrate the methodology. It relies on a concept called the vehicle accumulation profile (VAP) which serves to derive parking use throughout a typical weekday and days of the week. The method allows preserving all the attributes of the car driver, making it possible to analyze parking patterns by type of parking, population segment, etc. Processing several Origin Destination surveys allows conducting longitudinal parking analysis. This paper illustrates the usability of such concept and confirms that household surveys can be systematically processed to provide typical parking usage, as they do for travel behaviors. The analysis reveals an increasing share of not moving vehicles, during a typical weekday, across the area from 1998 (20.6%) to 2008 (28.8%). Trends on parking duration and assumed capacity are also discussed.

Double parking (DP) is one of the key contributors to traffic congestion on urban streets. Double parking violations of commercial vehicles while they load and unload at delivery locations with insufficient curbside space can have significant negative impact on traffic. Motivated by the need to study such impact in urban cities, this paper utilizes parking violation records for New York City along with field data collected using video recording, and adopts a comprehensive modeling approach that combines available data with two types of models. The first is an M/M/infinite queueing model used to estimate double parking effect on the average travel time. The second is a micro-simulation model developed and calibrated to study individual and combined effects of various explanatory variables. Both models account for different effects of general vehicles and commercial trucks. Via case studies in Midtown Manhattan and Downtown Brooklyn (New York, US), double parking activities and driver behaviors are investigated and used for comparative analysis. The M/M/Infinite queueing model has been empirically validated using field data collected as part of this study. Comparison results show a good fit for uncongested traffic conditions. Micro-simulation results indicate different impact levels for 21 scenarios in four categories namely, travel demand, double parking locations, frequency, and durations. This study can provide traffic agencies a potential approach to quantify the impact of double parking in a large-scale network and insights into the management and alleviation of on-street parking problems including incentives for encouraging off-hour deliveries and more effective enforcement during peak hours. 

Many cities include minimum parking requirements in their zoning codes and provide ample parking for public use. However, parking is costly to provide and encourages automobile use, according to many site-specific studies. At the city scale, higher automobile use is linked to traffic congestion, environmental degradation and negative health and safety impacts, but there is a lack of compelling, consolidated evidence that large-scale parking increases cause automobile use to rise.

In this study, we apply the Bradford Hill criteria, adopted from the field of epidemiology, to determine whether increases in parking should be considered a likely cause of citywide increases in automobile use. We rely on prior research and on original data from nine U.S. cities dating back to 1960. We first establish a correlation and find that an increase in parking provision from 0.1 to 0.5 parking spaces per person is associated with an increase in automobile mode share of roughly 30 percentage points. We also demonstrate that a majority of the Bradford Hill criteria can be satisfied using the available data, which offers compelling evidence that parking provision is a cause of citywide automobile use. Given the costs associated with parking and its apparent effects on automobile use, our findings warrant policies to restrict and reduce parking capacity in cities.