Shared Mobility

The Smoothing Effect of Carpool Lanes on Freeway Bottlenecks

Cassidy, Michael J
Jang, Kitae
Daganzo, Carlos F
2008

Real data show that reserving a lane for carpools on congested freeways induces a smoothing effect that is characterized by significantly higher bottleneck discharge flows (capacities) in adjacent lanes. The effect arises because disruptive vehicle lane changing diminishes in the presence of a carpool lane. The effect is reproducible across days and freeway sites: it was observed, without exception, in all cases tested.Queueing analysis shows that the effect greatly reduces the times spent by people and vehicles in queues. By ignoring the smoothing effect at one of the sites we analyzed,...

Spatiotemporal Effects of Segregating Different Vehicle Classes on Separate Lanes

Cassidy, Michael J.
Daganzo, Carlos F.
Jang, Kitae
2008

Spatiotemporal analysis of real freeway traffic reveals that carpool lanes are not as damaging as previously reported. To the contrary, the analysis unveils a surprising benefit of carpool lanes that should be even greater when special lanes are used to segregate very different vehicle classes, such as buses and cars. The paper pursues this finding and shows how reserving lanes on freeways and city streets for bus-use only can favorably affect not just buses, but also cars.

HOV Lane Configurations and Safety Performance of California Freeways – An Investigation of Differential Distributions and Statistical Analysis

Jang, Kitae
Chan, Ching-Yao
2009

From a recent study of safety evaluation of HOV-equipped freeways, it was found that limited-access HOV lanes appear to have a safety performance disadvantage when measured by collision distribution or collision rates for the HOV lane alone and for the HOV and left lanes combined. This paper describes the work performed to verify the statistical significance of related findings. Several statistical tests were used: empirical cumulative density function (CDF), Kolmogorov-Smirnov Tests, and comparison of means based on Poisson Distributed Samples. The conclusion that continuous-access HOV...

Public Transit and Shared Mobility COVID-19 Recovery: Policy Options and Research Needs

Shaheen, Susan, PhD
Wong, Stephen, PhD
2020

While the COVID-19 crisis has devastated many public transit and shared mobility services, it has also exposed underlying issues in how these services are provided to society. As ridership drops and revenues decline, many public and private providers may respond by cutting service or reducing vehicle maintenance to save costs. As a result, those who depend on public transit and shared mobility services, particularly those without access to private automobiles, will experience further loss of their mobility. These transportation shifts will be further influenced by changing work-from-home...

Innovative Mobility: Carsharing Outlook Carsharing Market Overview, Analysis, And Trends.

Shaheen, Susan, PhD
Cohen, Adam
2020

Since 1998, 94 carsharing programs have been deployed in North America - 40 are operational and 52 are defunct. As of January 1, 2018, there were 18 active programs in Canada, 21 in the United States (U.S.), and one program in Mexico. In North America, carsharing membership totaled approximately 2,110,111 members sharing 23,376 vehicles. The three largest carsharing operators in the U.S. and Canada accounted for 91% and 86% of the total membership, respectively. Only one operator provided service in Mexico as of January 2018.

Impacts of Transportation Network Companies on Vehicle Miles Traveled, Greenhouse Gas Emissions, and Travel Behavior Analysis from the Washington D.C., Los Angeles, and San Francisco Markets

Martin, Elliot, PhD
Shaheen, Susan, PhD
Stocker, Adam
2021

Transportation Network Companies (TNCs) like Lyft, Uber, and their global counterparts have expanded around the world over the past decade and have changed the way that people travel around cities and regions. The individual mobility benefits provided by TNCs have been clear. Passengers can summon a vehicle quickly via smartphone from almost anywhere to take them almost anywhere, with advance communication on estimated wait time, travel time, and cost. TNCs may also provide users with added mobility benefits, especially for those living in areas where public transit service is infrequent...

Shared-Use Vehicle Systems

Shaheen, Susan
2002

In recent years, shared-use vehicle systems have garnered a great deal of interest and activity internationally as an innovative mobility solution. In general, shared-use vehicle systems consist of a fleet of vehicles that are used by several different individuals throughout the day. Shared-use vehicles off the convenience of the private automobile and more flexibility than public transportation alone. These systems are attractive since they offer the potential to lower a user’s transportation costs; reduce the need for parking spaces in a community; improve overall air quality; and...

Shared Mobility in Low- and High-Income Regions

2022

Although shared and informal transport are not new concepts in low- and middle- income countries (LMICs), a variety of economic, environmental, and social forces are contributing to the growth of shared mobility in LMICs around the world. Shared mobility—the shared use of a vehicle, motorcycle, autorickshaw, minibus, scooter, bicycle, or other travel mode—is an innovative transportation strategy that enables users to have short-term access to a transportation mode. This paper documents key shared mobility and informal transport concepts, terms, and definitions around the world. The paper...

One-Way Carsharing's Evolution and Operator Perspectives from the Americas

Shaheen, Susan, PhD
Chan, Nelson
Micheaux, Helen
2015

Classic roundtrip carsharing has been documented as a strategy to reduce car ownership and vehicle miles/kilometers traveled in urban areas. The expansion of carsharing and other forms of shared-use mobility have led to a growing interest in understanding the latest models. In recent years, one-way carsharing has gained momentum across the globe with 18 operators providing services in ten countries worldwide. One-way carsharing does not require its users to return the vehicle to the same location from which it was accessed (in contrast to roundtrip carsharing). Users typically pay by the...

Mobility and the Sharing Economy: Potential to Overcome First- and Last-Mile Public Transit Connections

Shaheen, Susan, PhD
Chan, Nelson
2016

Shared mobility—the shared use of a motor vehicle, bicycle, or other mode—enables travelers to gain short-term access to transportation modes on an as-needed basis. The term “shared mobility” includes the modes of carsharing, personal vehicle sharing (peer-to-peer carsharing and fractional ownership), bikesharing, scooter sharing, traditional ridesharing, transportation network companies (or ridesourcing), and e-Hail (taxis). It can also include flexible transit services, including microtransit, which supplement fixed-route bus and rail services. Shared mobility has proliferated in global...