首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
This paper analyzes personal and car-sharing characteristics of commuters at university in Los Angeles, California. These commuters do not hold an on-campus parking permit and commute by an alternative mode other than driving alone. Each month, the university offers them 8 h free use of shared vehicles across the campus. University employee car-sharers’ housing distribution is significantly different from that of their counterparts who drive to work. Commuter benefits influence not only the participation rate of a car-sharing program but also the program participants’ frequency, time and quantity of car-sharing consumption. Car-sharing is most popular among bus commuters, university students and female employees.  相似文献   

2.
This study examined the trip-making behavior of persons over 65 years of age residing in Los Angeles County. To date, the major shortcoming of most research concerned with the transportation needs of the elderly is that the aged have been treated as a homogeneous group without recognizing the various lifestyles of the senior population. The two most easily distinguishable groups of elderly persons within the county are those residing in the inner-city and those around the urban fringe. Although many elderly are still found in gray ghettos there is currently a trend toward a more suburban generation of retirees. Four areas were selected within the county that reflected these two living patterns of the elderly. A comparative analysis of trip patterns and socio-economic data was completed. It was found that the suburban elderly are characterized as (1) having higher incomes, (2) residing predominantly in single-family units and (3) being reliant upon automobile transportation. As is typical of a large proportion of those over 65 years of age, many of the suburban elderly cannot drive. Studies of the transportation needs of this group indicate that without transit alternatives they may well become society's most transit-deprived segment. On the other hand, while the inner-city elderly may have a wider range of transportation options, they also have a distinct economic disadvantage which preludes their accessibility to opportunities. An analysis of modal choices, trip purposes and the frequency of travel exhibited many similarities and some significant differences in the travel behavior as well as problems of these two groups.In addition to investigating travel patterns a survey of taxi-cab use on weekends and weekdays was undertaken. Elderly persons represent a substantial proportion of taxi-cab patrons. Their use of taxis is further indicative of the change that occurs in mobility patterns upon reaching retirement. This mode of transportation is presently the only type of demand-responsive service available to the senior population in some parts of the county.This report was produced as part of a program of Research and Training in Urban Transportation sponsored by the Urban Mass Transportation Administration of the U.S. Department of Transportation. The results and views expressed are the independent products of university research and are not necessarily concurred in by the Urban Mass Transportation Administration of the Department of Transportation.  相似文献   

3.
4.
Travel by a Personal Rapid Transit (PRT) system may be much more energy efficient than travel by conventional road transport. The difference could be so large that the energy invested in the PRT infrastructure may be equivalent to the fuel that is saved by previous car and bus riders in less than five years. We analyzed the propulsion energy requirements of a PRT system and made a first-order calculation of the energy cost of the infrastructure and maintenance. Operation of the PRT requires only half the energy required by buses and a quarter of the energy used by passenger cars per passenger kilometer. The energy used to build the PRT infrastructure in a city may be recovered in five years if 10% of the car drivers switch to the PRT.  相似文献   

5.
This paper analyzes the impact of the transportation system management (TSM) program employed during the 1984 Los Angeles Summer Olympics. Two issues are examined. First, the impact of the various elements of the TSM program on transportation system performance is measured by conducting a series of traffic simulation studies. The results show that TSM was an important contributing factor in the favorable traffic conditions experienced during the Olympics. Second, the potential of employing TSM as a long-term transportation policy strategy is assessed. It is concluded that the travel behavior changes that occurred in response to the TSM program were unique and short-term. Under ordinary circumstances, incentives do not exist to induce changes of the magnitude observed during the Olympics.  相似文献   

6.
This paper first introduces the key players involved in the deployment of Intelligent Transportation Systems (ITS) technologies in the Los Angeles metropolitan area. The paper then reports the local deployment status of major Advanced Public Transportation Systems (APTS) projects, with a particular emphasis placed on the burgeoning Los Angeles Smart Shuttle Demonstration Project. In addition, the paper analyzes some technical, political, financial and other issues centering around the deployment of APTS technologies in the Los Angeles metropolitan area.  相似文献   

7.
The problem of precise longitudinal control of vehicles so that they follow predetermined time-varying speeds and positions has been solved. To control vehicles to the required close headway of at least 0.5 sec, the control philosophy is different from but no less rigorous than that of railroad practice. The preferred control strategy is one that could be called an “asynchronous point follower.” Such a strategy requires no clock synchronization, is flexible in all unusual conditions, permits the maximum possible throughput, requires a minimum of maneuvering and uses a minimum of software. Since wayside zone controllers have in their memory exactly the same maneuver equations as the on-board computers, accurate safety monitoring is practical. The paper discusses the functions of vehicle control; the control of station, merge, and diverge zones; and central control.  相似文献   

8.
Maintaining and enhancing public transit service in Indian cities is important, to meet rapidly growing mass mobility needs, and curb personal motor vehicle activity and its impacts at low cost. Indian cities rely predominantly on buses for public transport, and are likely to continue to do so for years. However, the public bus transit service is inadequate, and unaffordable for the urban poor. The paper explores the factors that contribute to and affect efforts to improve this situation, based on an analysis of the financial and operational performance of the public bus transit service in the four metropolitan centres and four secondary cities during the 1990s. Overall, there were persistent losses, owing to increasing input costs and declining productivity. The losses occurred despite rapidly increasing fares, and ridership declined. The situation, and the ability to address it, is worse in the secondary cities than the metropolitan centres. We suggest a disaggregated approach based on the needs and motivations of different groups in relation to public transit, along with improved operating conditions and policies to internalize costs of personal motor vehicle use, to address the challenge of providing financially viable and affordable public bus transit service.  相似文献   

9.
Brown  Anne  LaValle  Whitney 《Transportation》2021,48(2):1007-1031
Transportation - For decades, taxis have provided for-hire vehicle service without significant competition from other modes. But in 2012, ride-hail services such as Uber and Lyft upended the taxi...  相似文献   

10.
We have collected information on 46 bus rapid transit (BRT) systems throughout the world to investigate the potential patronage drivers. From a large number of candidate explanatory variables (quantitative and qualitative), 11 sources of systematic variation are identified which have a statistically significant impact on daily passenger-trip numbers. These sources are fare, headway, the length of the BRT network, the number of corridors, average distance between stations; whether there is: an integrated network of routes and corridors, modal integration at BRT stations, pre-board fare collection and fare verification, quality control oversight from an independent agency, at-level boarding and alighting, as well as the location of BRT. The findings of this paper offer important insights into features of BRT systems that are positive contributors to growing patronage and hence should be taken into account in designing and planning BRT systems.  相似文献   

11.
The safety of personal rapid transit systems involves careful attention to all features of the design such as the use of a hierarchy of fault-tolerant redundant control systems, bi-stable fail-safe switching, back-up power supplies, vehicle and passenger protection, and attention to the interaction of people with the system. Safety, together with reliability and adequate capacity, must be achieved while making the system economically attractive, hence techniques to achieve these goals at minimum life-cycle cost are primary in PRT design. Building on theory of safe, reliable, environmentally acceptable, and cost-effective design of PRT systems developed during the 1970′s, in 1981 the author and his colleagues initiated design of a new PRT system, now called Taxi 2000. The paper describes the relevant features of Taxi 2000 and principles of safe design incorporated into it.  相似文献   

12.
This paper presents two time series regression models, one in linear form and the other in logarithmic form, to estimate the monthly ridership of a single urban rail rapid transit line. The model was calibrated for a time period of about six and a half years (from 1978–1984) based on ridership data provided by a transit authority, gasoline prices provided by a state energy department, and other data.The major findings from these models are: (1) seasonal variations of ridership are –6.26%, or –6.20% for the summer period, and 4.77%, or 4.62% for the October period; (2) ridership loss due to a station closure is 2.46% or 2.41%; and (3) elasticities of monthly ridership are –0.233 or –0.245 with respect to real fare, 0.113 or 0.112 with respect to real gasoline price, and 0.167 or 0.185 with respect to real bridge tolls for the competing automobile trips. Such route specific application results of this inexpensive approach provide significant implications for policymaking of individual programs in pricing, train operation, budgeting, system changes, etc., as they are in the case reported herein and would be in many other cities.  相似文献   

13.
The choice of fare policy is more flexible in personal rapid transit than in conventional transit and has some unique aspects. The implementation of fare policies as a function of distance are discussed, and, following a discussion of how the fare would be collected in a PRT system, consideration is given to whether the fare should be per person or per vehicle.  相似文献   

14.
This note derives an equation for the ratio of the maximum possible station flow to average line flow in a personal rapid transit or dual-mode system using fully synchronous control. It is shown that such a system is impractical except in very small networks.  相似文献   

15.
Shin  Eun Jin 《Transportation》2020,47(2):475-501

This study investigates the disparities in access to various types of opportunities in ethnic neighborhoods, as compared to wealthy white neighborhoods (the reference). Focusing on the heterogeneity within ethnic neighborhoods, I distinguish between different types of neighborhoods based on their racial/ethnic makeup and median household income. The Los Angeles region provides an interesting empirical setting because of its racial diversity and its auto-centric spatial structure. The results show that the various types of ethnic neighborhoods differ not only in spatial patterns within the region but also in terms of relative access to opportunities. Nevertheless, I find that all types of the low-income ethnic neighborhoods have higher levels of access to jobs and non-work opportunities, except for access to parks/open spaces, than do the reference neighborhoods. This holds true regardless of accessibility measures and travel modes. However, the relative access to opportunities for middle-to-high-income ethnic neighborhoods varies by accessibility measure. Considering that each accessibility measure has its own set of meanings and planning implications, diverse measures should be taken into account for policy interventions. The present study also adds further evidence of modal disparities, which are much greater than spatial disparities, in access to opportunities.

  相似文献   

16.
The paper begins with a review of the rational for development of personal rapid transit, the reasons it has taken so long to develop, and the process needed to develop it. Next I show how the PRT concept can be derived from a system‐significant equation for life‐cycle cost per passenger‐mile as the system that minimizes this quantity. In the bulk of the paper I discuss the state‐of‐the‐art of a series of technical issues that had to be resolved during the development of an optimum PRT design. These include capacity, switching, the issue of hanging vs. supported vehicles, guideways, vehicles, control, station operations, system operations, reliability, availability, dependability, safety, the calculation of curved guideways, operational simulation, power and energy. The paper concludes with a listing of the implications for a city that deploys an optimized PRT system.  相似文献   

17.
18.
This paper explores the role of transit alternatives analyses, as defined by UMTA/FHWA technical requirements, in urban-transit decision-making. Case studies involving the Southwest Corridor of Chicago and the Dallas Area Rapid Transit Authority are reviewed. Decision-maker information needs, which differed widely between the two case studies, are outlined in terms of an emphasis on 10–15 key indices, the highlighting of trade-offs between direct and indirect impacts, and the identification of criteria where decision-maker judgment should be applied. Planning products most useful to decision-makers are identified, including the clear exposition of intangible costs and benefits. Financial cash-flow analysis, as related to implementation staging, and the well-organized management of overall evaluation results were also found to be important planning outputs in the case studies considered. Suggestions for improving planning products and the flow of information center on continuing evidence of the need for quick-response travel-analysis methods, better use of trade-off graphics, and avoiding the dangers of information overload. Several lessons learned from the case studies are listed.  相似文献   

19.
20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号