Internal Trips Research Articles

Impact of corridor highway system on communities: Built environment and travel mode choices

Conventional corridor management has focused on travel speed and efficiency while ignoring interactions between highway corridors and surrounding areas. This study investigates the interaction between the corridor highway system and the built environment around highways by estimating sustainable mode choices with respect to the land use characteristics of surrounding corridor highways throughout 29 regions in the U.S. The results indicate that the D variables at the corridor level matter. D variables at the corridor level, such as activity density, job-population balance, percentage of accessible jobs within 10 min by car, intersection density, percentage of 4-way intersections, and transit stop density, were highly associated with internal capture, walking trips, and transit use. The neighborhoods with higher activity density, job-population balance, intersection density, and better employment accessibility by transit experienced reduced VMT. The likelihood of internal trips, walking trips, and transit use decreased with household size and income; the opposite signs were found with VMT. The regional gasoline price had significant effects on all trips. In conclusion, this study provides planning and transportation researchers and practitioners with new evidence on the importance of built environmental characteristics (D variables) to encourage sustainable mode choices in the proximate neighborhoods of corridor highways.

PROPOSING A MATHEMATICAL MODEL OF BALANCING THE INVENTORY OF MULTI-ZONE BICYCLE SHARING SYSTEMS WITH MOBILE STATIONS AND APPLYING MAINTENANCE CONSTRAINTS

Regarding the necessity of developing transportation infrastructures and its increasing importance in urban issues, nowadays in different cities, bicycles are considered the main and sustainable vehicle along with walking and drawing more attention day by day. The case considers highly paramount since preservation of the environment, natural resources, and energy is one of the significant pillars of sustainable development, and urban transportation intensively influences it. Thus, Bicycle Sharing System (BSS) is recognized as an innovative urban transportation option that meets the citizens’ demand for commuting during the day. The BSS can highly affect the level of citizens’ health, and it can be counted as one of the leading health programs whether it’s added to the public transportation system, it can help the culture to be created to use bicycles instead of cars in most of the internal trips, and also it can be so influential in decreasing the air pollution and in the following its harmful effects on health issues. The mathematical model of rebalancing multi-zone BSS with mobile stations and applying maintenance constraints in a static status is considered in this research. The objective function of this research is a single-objective one, which is modeled with the aims of reducing the costs of traveled distances by the tracks within and outside the zones, reducing the costs of intact and defective bicycles transportation within and outside the zones, and eventually, reducing the costs of surplus bicycles depot at the stations. This issue is a multi-product one that includes different types of bicycles and balancing tracks. Computational results confirm the model’s efficiency. Also, sensitivity analysis has been done to prove that the model is affected by both parameters of storage costs of surplus bicycles and transportation costs within and outside the zones.

Optimized Zone Sizes and Headways for Flexible-Route Bus Services — A Two Zone Case

Flexible-route bus services are preferable in areas with low travel demand, since they can reduce travel time and costs, as well as improve accessibility, especially for people who are elderly or have disabilities. A flexible-route bus system serving two arbitrarily shaped zones is studied here. Zone sizes and headways are jointly optimized to achieve minimum average cost per passenger-kilometer. Three types of demand are considered: 1) trips between a service zone and a central business district (CBD); 2) trips between service zones; 3) internal trips within zones. Both coordinated and uncoordinated operation are modeled and then compared in numerical examples. Sensitivity analyses show the need for restricting the minimum zone area if minimum service requirements must be satisfied. A three-step procedure is introduced to determine an appropriate lower bound.

Land use variables affecting travel behaviour: a review

Research on the impact of land use variables on travel behaviour is reviewed. The focus is on density as an important measure of land use and its interaction with transportation systems. The effect of density was first addressed decades ago, so research published since the 1960s was reviewed. The reviewed works were classified into two groups according to the most commonly used measure of density and the most common variables of travel behaviour. The first group comprised 26 studies published before 2000 and the second group comprised more than 45 studies published after 2000. Population density was the main density term used in the first group while employment density and configurations of densities were integrated as measures in the second group. A direct relationship between mode choice and journey length was established. However, knowledge gaps were also identified, such as the effect of density on trip generation rate, type of trip according to trip purpose, internal and external trips, and trips on weekdays and weekends.

Analysing the Effects of Land Use on the Choice of Intra-Zonal Trip Destinations – A Comparison Between Weekday and Weekend Travel

Among the studies on the land use – travel relationship, few investigated it regarding weekend travel and destination choice. This study accordingly evaluates how the land use - destination choice relationship differs between weekdays and weekends using two multinomial logistic regression models in which the destination is classified into three types: microzone inside, microzone outside - macrozone inside, and macrozone outside. Major findings are that the choice of automobile alternatives for travel and their ownership are associated with the choice of the microzone inside while employment and income contribute to external trips. Among land use variables, nighttime population density turns out to be the only land use variable that consistently increases internal trips in all cases, regardless of the zone size and weekday - weekend difference, whereas daytime population density does not become significant in any case. Also, land use entropy and street connectivity are found to discourage a trip that moves from the microzone to the macrozone and transit system variables to facilitate a trip that goes beyond the microzone. Particularly, between two types of transit system variables, the choice of the microzone is likely to be associated with low bus stop density on weekdays and low metro station density on weekends.

Traffic generated by mixed-use developments—A follow-up 31-region study

This study aims to improve a previously-developed methodology for predicting the traffic impacts of mixed-use developments (MXDs). In 31 diverse metropolitan regions across the United States, we collected consistent regional household travel survey data and computed built environment characteristics—D variables—of MXDs. Multilevel modeling (MLM) was employed to predict the probability of trips captured internally within MXDs, walking on internal trips, and travel mode choice on external trips, by trip purpose. Larger, denser, mixed-use, and more walkable MXDs show a larger share of trips internally, compared with conventional suburban developments. Those MXDs with good access to transit, employment, and destinations also show higher levels of walking, biking, and transit shares on external trips, thus helping to reduce traffic impacts on the external road network. Perhaps the most impressive finding is that well-designed MXDs have walk shares of more than 50 percent on internal trips. A k-fold cross-validation supports the robustness of our analyses.

An Analysis of the Relationship between Land Use and Weekend Travel: Focusing on the Internal Capture of Trips

Weekend travel has not been duly considered in academics and practice regarding its relationship with land use. A lack of consideration is notable in terms of how land use internalizes weekend travel. Thus, by separating the internal and external travel of the traffic analysis zone, this study analyzes the land use effect on weekend travel in comparison with that on weekday travel. Two structural equation models, each of which is specified for weekday and weekend travel, construct the same sample and their results become comparable. At the travel variable level, the models find consistent results: Stronger effects are made on internal travel than on external travel and particularly, on trip frequency than on travel time. This implies that compact land use causes a stronger addition of internal trips and a less strong reduction of external trips, that is, changes in destinations rather than in total travel time. At the factor level, unlike the weekday model in which the sociodemographic factor exerts a stronger effect, the weekend model presents that land use more strongly affects travel patterns. This magnitude difference is explained by the different flexibility of compulsory weekday travel and discretionary weekend travel in relation to the choice of trip destination and frequency.

Diversity in the Traditional Musical Kurdish Themes and the Tourist Attraction

Abstract. The present study has tried to associate the themes of Kurdish music with tourist attraction activities. On the other hand, it has tried to pave the way to attract cultural tourists to Kurdistan through theme diversity and inspiration by natural ecological phenomena and also to attract those tourists with different tastes who are interested in local and traditional music. To achieve the above goals, different methods have been used including interviewing with celebrities, using existing resources such as audio versions of the traditional Kurdish music in the form of DVDs, CDs and also its video versions. Kurdish language is one of the most original languages in Iran that over the time has maintained its identity despite foreigners' onslaught and has not been subjected to too many changes. Many experts have expressed that the traditional Kurdish music is one of the richest traditional Iranian music. Using different themes, inspiring by ecological and natural phenomena and also social and cultur-al themes are some of the characteristics of the Kurdish music.Taking advantages of the available potentials in each region promotes the Iranian tourism identity all around the world. Using traditional Kurdish music along with the other attractions in the Kurdistan region improves the internal or domestic tourism. In addition to increasing the internal trips, it establishes friendship among people all around the country (Iran).

Challenge of Public Transport Planning in Private Vehicle Dominated Community

Daily trips in many Asian developing cities mainly rely on private vehicles. This paper presents a challenge of public transport planning in private vehicle dominated community. The case study was at Prince of Songkla University, in the southern Thailand. Electric bus service has been provided for internal trips within the campus. However, the bus service does not attract to the students and staff, influenced by private vehicles (motorcycle and passenger car). The Stated Preference (SP) technique was applied to evaluate travelers' responses to different policies in encouraging the modal shift from private vehicles to public transport. Binary logit models were developed and applied to evaluate different policies. The results show that the integrated policies between improvement of bus service (travel time and waiting time reduction) and management of private vehicle parking (parking limitation and pricing) could promote the bus system and reduce CO₂ emission in the community.

Traffic Emissions and Air Quality near Roads in Dense Urban Neighborhood

A traffic simulation was developed for a dense neighborhood in the city of Montreal, Quebec, Canada (8,656 links), and was linked with a regional traffic assignment model, which was used to determine the travel demand originating in and destined for the study area. With a version of the U.S. Environmental Protection Agency's Motor Vehicle Emissions Simulator model fit with local data, traffic emissions for each link were simulated by the use of instantaneous speed profiles. Emissions of greenhouse gases (GHG), oxides of nitrogen (NOx), and carbon monoxide (CO) were modeled under a range of regional and local policies, including fleet renewal, street closures, reduced demand, reduced internal car trips, and reduced through traffic. Several traffic scenarios were modeled in the traffic assignment and simulation models to represent these policies. Because of the high congestion levels in the neighborhood under base case conditions, limited networkwide reductions in emissions were observed, except in the scenario that aimed to reduce through traffic (29% reduction in GHG emissions compared with that in the base case scenario). Significant changes in the spatial patterns of emissions were detected. Average and instantaneous speed-based estimates were also compared; the average speed mode tended to overestimate total emissions as network speeds decreased. Finally, dispersion modeling was conducted along selected corridors to evaluate the effects of different scenarios on air quality. The study found significant increases in air pollution as a result of the street closure scenario and significant decreases with the reduced through traffic scenario.

교통인프라와 통행행태를 기반으로 한 통합적 형평성 분석: 경기도를 중심으로

본 연구는 지역간 형평성을 분석하기 위하여 교통인프라지표와 통행행태를 통합적으로 고려하였다. 교통인프라지표로는 도로시설, 대중교통시설, 지역특수지수를 이용하였다. 통행행태는 1일자의 버스교통카드데이터를 이용하였다. 공간군집 분석과 전역적 국지적 분석을 통해 얻은 결과 분석단위를 읍 면 동으로 하였을 때 해당지역과 주변지역의 인프라수준이 높은지역(High-High)에서 모두 낮은지역(Low-Low)등 4개의 수준으로 구분되었다. HH type의 지역에서는 버스이용자, 통행, 환승 수가 높고, LL Type의 지역은 내부통행수, 통행시간, 통행거리, 통행속도, 요금항목이 높게 나타났다. 전역적 회귀분석에 의해 교통인프라 수준을 통행행태 변수로 회귀한 결과, 버스이용자수(bus users), 평균환승수(mean_trans), 평균내부통행수(mean_inside), 평균통행속도(mean_speed), 총 4개의 통행특성 변수가 유의하게 추출되었다. 이들 변수를 적용하여 국지적 회귀분석(GWR)을 수행한 결과 전역적 회귀분석에 비해 AIC와 ANOVA 결과 모두 모형의 결과를 유의하게 향상시켜, 경기도 내 통행행태 특성이 교통인프라 수준을 설명하는 데 있어 지역 간 차이가 많이 존재하는 것을 다시 한 번 확인시켜주었다. This study aims at analyzing transportation equity between geographical areas of Gyonggi Province, by taking both the transportation infrastructure and travel behavior into account. Indicators of transportation infrastructure include the indices of road infrastructure, transit infrastructure and regional characteristics. Travel behavior concerns information from bus card data on a survey day. The hot-spot analysis conducted included spatial cluster analysis and global/local regression analyses. The analysis results identified geographical areas of four different classes of transportation equity, from the area with high level infrastructure surrounded by the areas with high level infrastructure (HH) to the area with low level surrounded by the areas with low level (LL). The area of HH type showed big numbers of passengers, trips and transfers, whereas the area of LL type shows big figures of internal trip frequency, travel time, travel distance, travel speed and transit fare. Global regression analysis showed that number of passengers, number of transfers, number of internal trips and mean travel speed are important to the level of transportation infrastructure. GWR with these four significant variables significantly improved the AICs and ANOVA results, which implies that the infrastructure is likely explained by travel characteristics differently between geographical areas in Gyonggi Province.

Mixed-Use Development Trip Generation Model

The mixed-use development (MXD) trip generation model provides a mechanism for estimating vehicle, walking, and transit trips for an MXD. The model applies trip modifications to standard single-use trip generation estimates developed by ITE. MXDs with diverse internal activities have been shown to capture internal trips at a rate higher than conventional suburban developments; therefore, the MXD trip generation model accounts for the internal capture of MXD sites by reducing the external trips produced and estimating the number of walking and transit trips that would typically be conducted by automobile. In addition, MXDs in central areas have been shown to generate shorter vehicle trips, and this factor has been taken into account in the model, as internal and external vehicle miles traveled (VMT) are estimated on the basis of published travel characteristics of MXDs. The MXD trip generation model provides a straightforward method of testing transportation-related metrics of MXDs. The model uses ratios from a leading research-based MXD model to reduce ITE vehicle trip estimates and presents a summary of results that show the effects on VMT, internal capture, and mode split as a result of enhanced activity density and diversity of land uses within the MXD. The MXD trip reductions are based on a methodology that analyzed data sets for 239 MXDs in six large and diverse metropolitan regions. Benefits of locally calibrated characteristics on vehicle ownership are also included in the mode split of the trip estimates of the MXD trip generation model.

A Case Study of Induced Trips at Mixed-Use Developments

Conventional thinking suggests that pedestrian-friendly, mixed-land-use developments will contribute to an overall reduction in travel by providing an alternative to automobile travel. However, these elements may serve to increase travel demand by reducing the overall cost of travel—a phenomenon generally known as 'induced' travel. To date, most studies of induced travel have focused on aggregate travel patterns, without examining how development patterns may influence people's trip-making decisions. To fill a void in the empirical research, we examine the potential for induced trip making at mixed-use developments by analyzing data obtained from a survey of travelers at a typical mixed- use site in suburban Dallas, Texas, USA. Our analysis found that during both the morning and afternoon study periods, at least some percentage of internal trips at the case-study site were induced, and not 'captured' from the external street network as is typically assumed. Induced trips by land-use pair and travel mode are also reported. Even with the induced trips, a reduction in regional vehicle-miles traveled can still be realized at mixed-use developments sites due to the propensity for those trips to be made on foot. Induced travel also has implications for the development of traffic-impact studies for proposed mixed-use sites, which generally assume that all internal trips are replacing external trips. Planners, policy makers, politicians, and other stakeholders exploring mixed-use developments are encouraged to consider the implications of induced travel in the mixed-use environment as a land-use solution to urban traffic congestion and air-quality issues.

Spatial Economic Model for Forecasting the Percentage Splits of External Trips on Highways Approaching Small Communities

The main difficulty in forecasting traffic volumes in small urban communities is identifying the amount and destination of the external traffic. Three methods exist for determining the percentage of external traffic destined for the study community (external–internal trips) or through the study community (external–external trips): a comprehensive origin–destination study, a cordon line origin–destination study, and the use of regression equations. This paper examines the possibility of the use of an alternative technique, based on a spatial economic model, to determine the traffic distribution. The project uses an economic model, which includes surrounding community factors, to determine the trip rates for three communities within Alabama and compares the results obtained from this model with the results given by a commonly accepted regression equation and a recently completed cordon line origin–destination study performed by using video surveillance. It is demonstrated that the economic model performs well for the case study cities, and this model is recommended for use in providing estimates that incorporate a community's economic relationship to neighboring towns for traffic forecasting.

Evaluation of Network Preloads on a Medium-Sized Urban Travel Forecast Model

Transportation engineers and planners attempt to understand urban travel characteristics to develop, formulate, and analyze problems and opportunities better. Transportation professionals use urban transportation models and typically implemented the four-step urban transportation planning process. This study examined a modified planning process that preassigned external trips to the transportation network before distributing and assigning internal trips. The preassignment, or preloading, of external trips helped to ensure that trips passing through the network were assigned to only the major through routes and that internal trips were modeled with the knowledge that external trips were present on the roadways before selecting destination or route. The study concluded that the preload methodology did not affect the validity of a travel model in a medium-sized urban travel forecast model and reduced assignment error on minor arterial roadways, which would not be the typical routes used by external travelers, to a level below the maximum deviation where an incorrect decision would be made regarding improvements to the roadway infrastructure.

Innovative Approaches to Regional Freight Transportation Planning: Case Study of Monterey Bay Region

How a California metropolitan planning organization (MPO) overcame data limitations and developed innovative solutions to regional agricultural freight transportation problems is described. Data from government agencies and trade groups on annual fruit and vegetable production, fish landings, and wine production were combined with survey data on truck volumes and loading practices to develop novel approaches for estimating truck and rail trips. Similar methods were used to project future freight volumes by using key population, income, and agricultural productivity indexes to project agricultural production volumes and employment forecasts in the processed food industries and thereby forecast freight volumes in their industries. To identify problems and deficiencies in the system, new performance indicators such as number of internal truck trips per outbound line-haul trip, wait time per pickup, comparisons of hourly inbound and outbound line-haul truck trip distributions, and truck trips as a percent of total traffic volume on roadways with poor level of service were used. It was concluded that poor logistics planning, lack of coordinated information and communications about load availability, poor load consolidation practices, and inadequate truck parking and driver waiting facilities were among the biggest problems facing the region. A proposed freight logistics center, which may be developed as a public-private partnership, is now under consideration. The methods and programs developed in this study may have applications in other small to medium-sized MPOs.

Innovative Approaches to Regional Freight Transportation Planning: Case Study of Monterey Bay Region

How a California metropolitan planning organization (MPO) overcame data limitations and developed innovative solutions to regional agricultural freight transportation problems is described. Data from government agencies and trade groups on annual fruit and vegetable production, fish landings, and wine production were combined with survey data on truck volumes and loading practices to develop novel approaches for estimating truck and rail trips. Similar methods were used to project future freight volumes by using key population, income, and agricultural productivity indexes to project agricultural production volumes and employment forecasts in the processed food industries and thereby forecast freight volumes in their industries. To identify problems and deficiencies in the system, new performance indicators such as number of internal truck trips per outbound line-haul trip, wait time per pickup, comparisons of hourly inbound and outbound line-haul truck trip distributions, and truck trips as a percent of total traffic volume on roadways with poor level of service were used. It was concluded that poor logistics planning, lack of coordinated information and communications about load availability, poor load consolidation practices, and inadequate truck parking and driver waiting facilities were among the biggest problems facing the region. A proposed freight logistics center, which may be developed as a public-private partnership, is now under consideration. The methods and programs developed in this study may have applications in other small to medium-sized MPOs.

Empirical Studies of Journeys to Work by Modes of Transport in Greater London: 1966 and 1971

With the use of 1971 journey-to-work census data for London, the spatial distributions of home and workplace locations at different distances from the city centre were analysed for the main modes of transport. The relationships among the fundamental quantities such as density, trip length, modal split, and level of car ownership were also investigated. These analyses were compared with those of corresponding 1966 data. The comparisons show that although the home density in 1971 within the first 2 km from the city centre decreased by approximately 21%, while the workplace density decreased only by approximately 4%, the actual number of workplaces within this range of distance fell by about 2·5 times that of the homes. The overall decrease in homes and workplaces resulted in a 9% drop in the total number of internal trips for London as a whole. Resolving these trips by modes of transport shows that rail, bus, and walk trips had decreased while car trips had increased. As a result, the most common mode of transport to work switched from bus in 1966 to car in 1971. This also contributed to the overall increase in the average trip length in 1971. The analysis on the level of car ownership for 1971 shows that more than 50% of the households located more than 12 km from the city centre had at least one car. On average, the number of cars per household in 1971 was approximately 0·64.

Activity center circulation: The competition between automated guideway transit and pedestrianization

This paper demonstrates why automated guideway transit (AGT) circulation systems should only be installed in those activity centers which are extensive enough that a large proportion of their internal trips will be too long to be covered on foot, even when pedestrian amenities are provided. Following a brief review of the essential characteristics of the various types of AGT, the significance of walking as a mode of transportation within compact activity centers is discussed, with emphasis on the competition walking can offer to AGT circulation systems. An analysis which compares the distributions of trip times for walking and AGT trips between the same set of activity center origins and destinations is then described and some of the implications of its results for the planning of activity center circulation systems are explained.