Travel Time Ratio Research Articles

Exploration of Statewide Fragmentation of Activity and Travel and a Taxonomy of Daily Time Use Patterns using Sequence Analysis in California

Sequence analysis is used in this paper to measure fragmentation in activity participation and travel. Fragmentation here is defined as the sequencing of many short and long activities and trips that happen in a personal daily schedule. Studying sequences of daily episodes (each activity at a place and each trip) is preferable over other techniques of studying activity–travel behavior because sequences include the entire trajectory of a person’s activity during a day while jointly considering the number of activities and trips, their ordering, and their durations. We first identify places visited and duration at each place on a minute-by-minute basis, then we derive representative daily behavior patterns using hierarchical clustering. Our study shows there are at least nine distinct daily patterns with different sequencing of activities and travel as well as travel time ratios and modal split. These patterns include typical commute to work or school, staying at home all day, or traveling extensively. As expected, day of the week plays a major role in the type of daily activity–travel patterns. Travel time ratios are also examined for each daily pattern and we find differences in the role played within each pattern between central city, suburban, exurban, and rural dwellers. In a comparison of couples, we find systematically higher fragmentation in households that have children and their parents are employed, with women showing higher fragmentation in the activity–travel patterns.

Operational Assessment of Public Transport: A Case of Kathmandu, Nepal

In absence of the railway at Kathmandu, Nepal, public transport effectiveness needs to be assessed. The paper aims to assess the operational performance of public transportation in Kalanki-Kalimati-Tripureshwor-Bhotahity forward 6700 m and backward 6200 m section of Kathmandu. Key Performance Indicators (KPI) for performance assessment were listed from the literature review and finalized through departmental expert consultation based on average mean score analysis of availability, cost of collection, quality and necessity of the data. Based on the finalized 4 KPI along with 29 micro KPI, performance of SajhaYatayat, bus and microbus were compared categorizing under economical, service, safety and people perception by collecting data through field survey. The economic analysis reveals that microbus has the highest internal rate of return and benefit cost ratio highest as 28.55% and 1.35 respectively while the bus has the highest revenue per kilometer and cost per kilometer as 104.94 and 79.012 respectively. Service indicators analysis reveals that SajhaYatayat has the highest travel time ratio and running time as 1425sec and 1.66, microbus has the highest journey time as 1555.86 sec, the bus has the highest running speed, journey speed and running index as 17.39 kph, 16.42 kph and 0.68 while traveling from Kalanki to Bhotahity respectively. The average passenger waiting index is 0.88. The affordability index of microbus is 4.47% respectively. Bus punctuality of SajhaYatayat is non-frequent but bus and microbus are Frequent. According to a schedule questionnaire survey with 94 respondents, the result of people perception indicators reveals that 21.27% of respondents are not satisfied with SajhaYatayat, bus and microbus. It is concluded that SajhaYatayat is performing better among three-selected public transport in the study route i.e. SajhaYatayat, bus and microbus are performing in decreasing order.

Operational Assessment of Public Transport: A Case of Kathmandu, Nepal

In absence of the railway at Kathmandu, Nepal, public transport effectiveness needs to be assessed. The paper aims to assess the operational performance of public transportation in Kalanki-Kalimati-Tripureshwor-Bhotahity forward 6700 m and backward 6200 m section of Kathmandu. Key Performance Indicators (KPI) for performance assessment were listed from the literature review and finalized through departmental expert consultation based on average mean score analysis of availability, cost of collection, quality and necessity of the data. Based on the finalized 4 KPI along with 29 micro KPI, performance of SajhaYatayat, bus and microbus were compared categorizing under economical, service, safety and people perception by collecting data through field survey. The economic analysis reveals that microbus has the highest internal rate of return and benefit cost ratio highest as 28.55% and 1.35 respectively while the bus has the highest revenue per kilometer and cost per kilometer as 104.94 and 79.012 respectively. Service indicators analysis reveals that SajhaYatayat has the highest travel time ratio and running time as 1425sec and 1.66, microbus has the highest journey time as 1555.86 sec, the bus has the highest running speed, journey speed and running index as 17.39 kph, 16.42 kph and 0.68 while traveling from Kalanki to Bhotahity respectively. The average passenger waiting index is 0.88. The affordability index of microbus is 4.47% respectively. Bus punctuality of SajhaYatayat is non-frequent but bus and microbus are Frequent. According to a schedule questionnaire survey with 94 respondents, the result of people perception indicators reveals that 21.27% of respondents are not satisfied with SajhaYatayat, bus and microbus. It is concluded that SajhaYatayat is performing better among three-selected public transport in the study route i.e. SajhaYatayat, bus and microbus are performing in decreasing order.

Give public transit a chance: A comparative analysis of competitive travel time in public transit modal share

Extensive research has found that people are more likely to choose the transport alternative which offers shorter travel time. But few studies approached the role of travel time across different transport alternatives and cities. This research assesses the influence of competitive travel time between car and public transit in public transit modal share for commute trips. São Paulo, New York, and Tokyo were selected to perform the analysis. A Fractional Logistic Regression in the binary form was drawn, and a competitive travel time index was calculated based on the Car/Public transit travel time ratio weighted by the number of the employed population at the origin and jobs at destinations in the absence of an Origin-Destination matrix. Findings suggest that, though car ownership was identified as the major factor, Car/Public transit travel time ratio is positively associated with the increase of public transit modal share. Furthermore, the Car/Public transit travel time ratio effect in public transit modal share consistently increases as people get increased access to cars.

Disparities in travel times between car and transit: Spatiotemporal patterns in cities

Cities worldwide are pursuing policies to reduce car use and prioritise public transit (PT) as a means to tackle congestion, air pollution, and greenhouse gas emissions. The increase of PT ridership is constrained by many aspects; among them, travel time and the built environment are considered the most critical factors in the choice of travel mode. We propose a data fusion framework including real-time traffic data, transit data, and travel demand estimated using Twitter data to compare the travel time by car and PT in four cities (São Paulo, Brazil; Stockholm, Sweden; Sydney, Australia; and Amsterdam, the Netherlands) at high spatial and temporal resolutions. We use real-world data to make realistic estimates of travel time by car and by PT and compare their performance by time of day and by travel distance across cities. Our results suggest that using PT takes on average 1.4–2.6 times longer than driving a car. The share of area where travel time favours PT over car use is very small: 0.62% (0.65%), 0.44% (0.48%), 1.10% (1.22%) and 1.16% (1.19%) for the daily average (and during peak hours) for São Paulo, Sydney, Stockholm, and Amsterdam, respectively. The travel time disparity, as quantified by the travel time ratio R (PT travel time divided by the car travel time), varies widely during an average weekday, by location and time of day. A systematic comparison between these two modes shows that the average travel time disparity is surprisingly similar across cities: R < 1 for travel distances less than 3 km, then increases rapidly but quickly stabilises at around 2. This study contributes to providing a more realistic performance evaluation that helps future studies further explore what city characteristics as well as urban and transport policies make public transport more attractive, and to create a more sustainable future for cities.

Impact of river reconstruction on groundwater flow during bank filtration assessed by transient three-dimensional modelling of flow and heat transport

Bank filtration (BF) is an established indirect water-treatment technology. The quality of water gained via BF depends on the subsurface capture zone, the mixing ratio (river water versus ambient groundwater), spatial and temporal distribution of subsurface travel times, and subsurface temperature patterns. Surface-water infiltration into the adjacent aquifer is determined by the local hydraulic gradient and riverbed permeability, which could be altered by natural clogging, scouring and artificial decolmation processes. The seasonal behaviour of a BF system in Germany, and its development during and about 6 months after decolmation (canal reconstruction), was observed with a long-term monitoring programme. To quantify the spatial and temporal variation in the BF system, a transient flow and heat transport model was implemented and two model scenarios, ‘with’ and ‘without’ canal reconstruction, were generated. Overall, the simulated water heads and temperatures matched those observed. Increased hydraulic connection between the canal and aquifer caused by the canal reconstruction led to an increase of ~23% in the already high share of BF water abstracted by the nearby waterworks. Subsurface travel-time distribution substantially shifted towards shorter travel times. Flow paths with travel times <200 days increased by ~10% and those with <300 days by 15%. Generally, the periodic temperature signal, and the summer and winter temperature extrema, increased and penetrated deeper into the aquifer. The joint hydrological and thermal effects caused by the canal reconstruction might increase the potential of biodegradable compounds to further penetrate into the aquifer, also by potentially affecting the redox zonation in the aquifer.

Circuity in China's high-speed-rail network

This study investigates the circuity of China's high-speed-rail (HSR) network from 2014 to 2016 and analyzes the network performance. The concept of circuity has been redefined in terms of travel time so that various speed levels of HSR lines can be measured systematically. In this study, circuity is redefined as the ratio of actual travel time to ideal travel time. By using actual HSR trip records, the influence of passenger demand and the circuity of transfer trips have been examined. At the node level, we find that the circuity of principal stations has significantly decreased overall. For stations with lower circuity, transfer trips from/to them tend to be more circuitous. Although stations along the intercity rail lines show higher circuity, they contribute to regional coverage and connectivity. Finally, we find that circuity tends to increase with a decreasing passenger flow for OD pairs within a certain distance range, and the passenger flow may decline as the OD distance increases.

Do cities or suburbs offer higher quality of life? Intrametropolitan location, activity patterns, access, and subjective well-being

Critics deride American suburbs as dull, aesthetically displeasing, socially isolating, unhealthy, environmentally unsound, and lacking in accessibility. However, the dramatic shift of the American population to the suburbs in the post-WWII period suggests suburban living may have advantages. Using data from the American Time Use Survey, this paper examines whether residence in a principal city versus the suburbs offers a more emotionally satisfying lifestyle. First, the findings show that demographically similar city residents and suburbanites engage in a very similar amount and composition of out-of-home activities. Second, the ratio of travel time to activity time for specific travel/activity couplets is lower for city residents for a few activities, and lower for suburbanites for others, but on the whole the differences in accessibility implied by these travel time prices are minor. Third, the activities in which city residents and suburbanites engage are associated with very similar degrees of subjective well-being (SWB), including both life satisfaction and affect. The most noteworthy difference between the two geographies is that suburbanites have modestly but measurably higher SWB than demographically similar urbanites in terms of feelings of happiness (hedonic affect), a sense of meaning (eudaimonic affect), and life satisfaction. These findings suggest that there may be advantages to suburban living.

Analysis of the Travel Time of Various Transportation Systems in Urban Context

Abstract What’s the maximum detour for ride pooling that is accepted from the passengers’ point of view? We address this question by determining the accepted detour of conventional public line transport, which is being accepted by its passengers. This is done using the Google Maps Routing application programming interface (API) for analyzing the travel times of different means of transport in 13 German cities. From the identified travel time ratios of public transport and motorized individual transport conclusions are drawn about the maximum reasonable detour when using ride pooling.

Restoration increases transient storages in boreal headwater streams

AbstractBed siltation can drastically alter the physical conditions of headwater streams and is therefore a stressor for stream ecosystems. We studied 32 headwater streams that represented near‐natural (reference; N = 11), sediment‐impacted (N = 12), or wood‐ (N = 4) or stone‐restored (N = 5) streams to quantify how extensive siltation and restoration with either large woody debris (LWD) or boulder structures influence transient storage conditions. We carried out repeated stream tracer experiments, field measurements of habitat characteristics, and numerical simulations to determine the effects of siltation and restoration on total transient storage. Compared with reference streams, impacted streams had a smaller storage zone cross‐sectional area (As/A) ratio and fraction of median travel time due to transient storage (F200), whereas restored streams had transient storage conditions similar to near‐natural conditions. Both of the two restoration methods had positive but differing impacts on bed sediment and transient storage properties. The LWD restoration created diverse total transient storage conditions, whereas boulder restoration decreased fine sediment cover. Addition of both LWD and boulders could thus aid the recovery of headwater streams from excessive sediment input and increase transient storage and in‐stream habitat complexity.

Estimating the Reliability of Travel Time on Railway Networks for Freight Transportation

&lt;p&gt;&lt;em&gt;Railway freight transportation is an important transport system that its reliability causes economic issues. Freight carriers require predictable travel times to schedule their programs in competitive environment, so the estimation of reliability of travel time is very important. The present study proposes a travel time index that estimates the reliability of railway freight transportation and evaluates performance as well. Travel time reliability is estimated based on the shortest path between O-D pairs. Statistical measures of travel time, defining as the ratio of the 95th percentile travel time and the shortest path mean travel time as an ideal travel time, for each obtained route are calculated according to their selected links. Experimental data on Iranian rail network has been used as case study and results revealed that the routes less than 400 kilometers should be improved in terms of their reliabilities, because they are less reliable than long distance routes.&lt;/em&gt;&lt;em&gt;&lt;/em&gt;&lt;/p&gt;

Electrical measurement of cross-sectional position of particles flowing through a microchannel

The first high-throughput system for the electrical detection of cross-sectional position and velocity of individual particles flowing through a rectangular microchannel is presented. Lateral position (along channel width) and vertical position (along channel height) are measured using two different sets of coplanar electrodes. In particular, the ratio of travel times measured with electrodes generating a current flow transverse or oblique with respect to particle trajectory yields lateral position. The relative prominence and transit time of a bipolar double-Gaussian signal obtained with a suited electrode configuration, respectively, supply vertical position and velocity. The operating principle is presented by means of finite element numerical simulations. The method is experimentally validated by comparing the electrical estimates of position and velocity of polystyrene beads with optical estimates obtained by processing high-speed images. The system is used to observe bead focusing at different particle Reynolds numbers. This system, providing a fully electrical characterization of single-particle motion, represents a powerful tool, e.g. to understand fluid motion at the microscale, in particle separation studies, or to assess the performance of particle focusing devices. Moreover, it can be simultaneously used to perform single-cell impedance spectroscopy, thus achieving an unprecedented multiparamteric characterization.

Model for Filtering the Outliers in DSRC Travel Time Data on Interrupted Traffic Flow Sections

This study aims to develop a model that effectively filters outliers in travel time data obtained by using the DSRC on interrupted traffic flow sections. To establish a direction for model development, we identified the characteristics of the DSRC system and existing abnormal data filtering models, causes of outliers in travel time data and their distribution center, changes in the travel time distribution according to the section length and existence of traffic congestion, variation in the number of data samples obtained, and the status of missing data. When an existing model is used to filter the abnormal travel time data obtained on the interrupted traffic flow sections, the mean and median values derived based on the asymmetry of the travel time distribution deviate from the center of the travel time distribution, which leads to fundamental errors in the estimation of the size of the normal travel time data distribution. Moreover, the performance of this model for filtering abnormal data decreases because of the distorted mean and standard deviation when outliers are mixed and optimizing filtering variables is difficult. To overcome these limitations of existing outlier filtering models, we developed a novel outlier filtering model by establishing a model development direction to improve the methods of obtaining data, setting the travel time distribution center, estimating distribution size, and filtering repetitive outliers. The performance of the developed model in filtering outliers is verified by comparing it with that of existing models for the intelligent transport systems installed on 13 types of single-sections and multi-section on the metropolitan national highway, Korea. The comparison indicates that the developed model generally exhibits the best performance for filtering abnormal data on all types of sections. The normal filtering ratio of the developed model was maintained at over 98.5% for all road types and traffic situations, demonstrating improvement of up to 27.4%. The error ratio of travel time at short interrupted traffic flow sections during non-congestion is significantly improved in this model.

Traffic congestion analysis using travel time ratio and degree of saturation on road sections in Palembang, Bandung, Yogyakarta, and Surakarta

Traffic performance have been measured based on degree of saturation, velocity, travel time, and delays. However, they weren’t enough to measure the traffic fluctuation that happen on normal days. This study aims to develop some modified analysis about traffic congestion based on the degree of saturation (DS) and travel time ratio (TTR). The travel time ratio is defined as a ratio between the travel time at peak hour and the travel time at off-peak hour in a certain road section. Traffic congestion conditions are classified into 4 categories: Peak-hour Congestion, Lengthy Congestion, Momentary Congestion, and Smooth Traffic. Based on survey results on road sections in Palembang, Bandung, Yogyakarta, and Surakarta, it can be concluded that peak-hour congestion occurs when TTR &gt; 1,40 and DS &gt; 0,75, lengthy congestion occurs when TTR &lt; 1,40 and DS &gt; 0,75, momentary congestion occurs when TTR &gt; 1,40 and DS &lt; 0,75, and smooth traffic when TTR &lt; 1,40 and DS &lt; 0,75.

Smart cities and value of time: An International Symposium

Travel time and activity time have been treated as separate notions, albeit with some assumed interdependencies. But, previous studies show that people accept noticeable higher travel time ratios when travelling by public transport compared with travelling by car. The cost of travel time is reduced as travel time is converted as activity time (towards the productive use). Furthermore, the impact of a high quality journey is an important issue in lifestyle and distribution of activities. The efficiency, safety and productivity of the journey can be expected to impact the value of time. And, the proportion of travel time saved, which can be used for other activities might have positive effects on the quality of life. In recent years some significant ICT-related innovations have been introduced to large shares of society, but research on the current relation between characteristics of ICT-use and its impact on mobility is limited. Development of smart cities and urban living labs is strongly affected by the ICT use and mobility patterns, as urban living labs co-create new products from collaboration between public, private and civic partnerships. At the same time, in certain self-constrained environments, activity duration has many effects in travel patterns for out-ofhome activities. Use of big data to model travel behaviour might bring important implications for individual mobility. Similarly, traffic safety and management of transport infrastructure are a main concern for government decisions in developing countries. This paper contains a summary of five keynote sessions of the Symposium Smart Cities and Value of Time, that took place in Santo Domingo, Dominican Republic in January 18 and 19 2018. This symposium aimed to contribute to the debate on planning transport system and urban development according to the needs and activities undertaken by citizens of the modern ‘on move’ society. This summary presents five key points of transport research oriented to smart cities and value of time, which can be mentioned as: user’s perspective (equity), data collection and infrastructure (traffic safety and network design). These topics are substantially important to estimate accurate travel demand models, and therefore design efficient transport measures.

Estimating freeway route travel time reliability from data on component links and associated cost implications

ABSTRACTTypically, data on travel time (speed) and traffic volume are collected for relatively short homogenous links of a roadway (e.g. every ½ to 2 miles or 0.8–3.2 km) and not for particular routes from origins to destinations. To accurately estimate a traveller’s trip, there is a need to build information on an entire route from data collected at the link level. Because it can be resource-intensive to define specific routes for the entire network of interest, route reliability performance measures are sometimes estimated using a vehicle-miles of travel (VMT)-weighted average of performance indices from links.In performance measurement, travel time index (TTI) is the ratio of average travel time and free-flow travel time while planning time index (PTI) is the ratio of 95th percentile travel time and free-flow travel time. TTI is considered a mobility measure while PTI reflects system reliability. Using indices based on free-flow (uncongested) travel time, this study finds that the VMT-weighting of link indices to get the corresponding route index gives reasonable results for the travel time index (TTI). However, this approach overestimates the planning time index (PTI). This highlights the statistical insufficiency of estimating route PTI values from link PTI values weighted by VMT. It points to the subsequent need to incorporate factors for dispersion and skewness characteristics of travel time distributions on constituent links. This paper introduces a promising method to estimate freeway route reliability considering these dispersion and skewness properties.For statewide Virginia Interstates considered here, economic analyses based on the value of travel time demonstrate that incorrect travel time reliability estimates result in upwards of 200% higher user costs. Researchers anticipate that the information documented in this paper will be useful for those conducting performance monitoring activities to estimate route reliability with limited resources when only link data are available.

Editors' Introduction

Editors' Introduction Hilda E. Kurtz and Deepak R. Mishra We are pleased to introduce the second issue of 2017. This issue of Southeastern Geographer once again showcases the diversity and energy of our discipline as it ranges across physical, human and techniques-oriented domains. William Graves and Ronald Kalafsky revisit Glasmeier and Leichenko's (1996) evaluation of the Southern economy in relation to the global economy. Examining geographies of economic evolution in the region, they find mixed results. The region has progressed in some measures relative to the nation, and regressed in others. The authors suggest linkages between their findings and region-wide wage structure and other policy stances. In "The work of southering: 'Southern justice' and the moral landscape of uneven racism", David Jansson suggests that scholars may inadvertently reproduce discourses of internal orientalism in analyses of the Southern region. After demonstrating the ways in which even analyses intended to unsettle stereotyping of the region may on some level reinforce sterotyping, Jansson suggests several pathways for avoiding such missteps. Jansson introduces several key concepts which readers of Southeastern Geographer are likely to find constructive. The paper by Ping Yin examined the gestational and trimester-specific association of high outdoor temperature and full-term birth weight and risk of low birth weight. The study found a significant but weak association of gestational or trimester-specific high temperature exposure with birth weight in Georgia between 2000 and 2006. No adverse effects of high outdoor temperature were found on low birth weight risk except for the number of hot days (days with temperature greater than 103°F) in the second trimester. Based on the weak association, the author concluded that the high outdoor temperature may not be a major threat to low birth weight in Georgia because of people's adaptive behavior. However, as climate change proceeds, it is important to understand how warming trends will affect the reproductive health in developing countries since this information can help guide local public health adaptation efforts. Mulrooney et al. developed a method to measure relative food availability using a raster or pixel based relative travel time index (PRTI). This study was part of a larger research project investigating rural food insecurity around Fayetteville, North Carolina, and the greater Fort Bragg area. PRTI represents the ratio of travel time to the nearest healthy food source versus that to the nearest unhealthy food source at the pixel level thus providing a more comprehensive visualization of food access in a specific geographic area. The authors found that in a four county region southeast of Fayetteville food swamps were prevalent in northern Robeson [End Page 110] County and a swath running through central Sampson County. They also found the percentage of minority residents was statistically higher in PRTI derived rural food swamps than non-food swamps and indicators related to low-income were found to be to be statistically significant than non-food desert counterparts. This research may improve our understanding of the spatial distribution of food swamps as well as interpretation of the food environment in any given region. In addition, this issue includes a full book review section. In short, the articles in this issue showcase scholarship that engages with geographic change at a wide geographic range and highlight the contemporary issues in the region. We conclude by inviting proposals for themed issues of Southeastern Geographer, as well as inviting readers to continuing submitting excellent work to the journal. If you would like to organize a themed issue, please send a 2-page proposal highlighting the summary, justification, list of specific research areas, and potential author names/affiliation (if already known) to Email: segeditors@uga.edu. [End Page 111] Hilda E. Kurtz and Deepak R. Mishra University of Georgia Copyright © 2017 Southeastern Division of the Association of American Geographers

Competition or Supplement? Tracing the Relationship of Public Transport and Bike-Sharing in Vienna

The ever-increasing popularity of bike-sharing schemes has added an additional mode to the transport regime in many cities. The data produced by lending and returning bicycles at geographically diverse stations has stimulated numerous studies. We focus on the City of Vienna bike-sharing system (CityBike Wien; CBW) and its relationship with the public transport system, asking whether bike-sharing serves as competitor, relief or supplement. We approach the question by surveying the total CityBike Wien trip data from 2015 – about 1 million records. We cleanse and route all bicycle trips and compare them with routed alternative public transport (PT) journeys in terms of travel time ratios and detour factors. After calculating and plotting the cumulative frequencies of travel times and distances of both modes of transport as well as comparing the current PT and CBW usage levels, we conclude that CityBike functions as a supplement to Vienna’s public transport.

How can public transit get people out of their cars? An analysis of transit mode choice for commute trips in Los Angeles

U.S. public transit agencies struggle to attract and retain riders. Unprecedented public investments have been made over the past several decades for expanding and improving transit service across cities. Unfortunately, however, there is no evidence of increase in ridership once growth in population and aggregate travel demand are accounted for. Consequently, the quest for boosting patronage continues. The challenge, experts argue, is to attract people out of cars.In this paper, I use a recent state-wide travel survey from California and take advantage of a new comprehensive historical archive of regional real-time multi-modal transportation system data to explore contexts in which persons belonging to car-owning households within Los Angeles County use transit for their commute.I find that few car owners use transit, and that lack of access to the household vehicle(s) explain choice of transit to a large extent. While discretionary transit use (or transit use by choice) is rare, I find evidence that fast (relative to car), frequent and reliable transit service along with fewer transfer requirements strongly correlate with car-owners’ transit mode choice. Home and workplace neighborhood density, proximity to transit stop, and availability of rail are other critical facilitators. Even if observed effects are due, in part, to self-selection, there are important lessons for transit planners. For example, results suggest that all else equal: reduction in transit-to-auto travel time ratio by unity can increase odds of transit mode choice by about 25%; reduction in headway by 10min can increase the odds by about 30%, and; lowering the standard deviation of schedule deviation from over to under three minutes can result in 2.6 times increase in the odds.This paper identifies effective strategies for increasing transit's competitiveness relative to auto, and hence attracting people out of their cars. While rail network expansion programs and transit-oriented development efforts must continue across U.S. cities, it is important that planners also advocate for investments in key dimensions of bus service quality that patrons value, such as speed, frequency and reliability. Efficient network designs that reduce transfer requirements, introduction of bus rapid transit services, and improvements in real-time operations, scheduling and long-range planning by using ITS (intelligent transportation systems) infrastructures across modes are critical. This study shows that careful planning can promote discretionary transit use by attracting existing latent demand and by creating new demand in an era of increasing government interest in transit and growing traffic congestion. Broader positive effects on the travelling public and the environment are much greater than what this study can predict.

Traffic Congestion in Dar es Salaam: Implications for Workers’ Productivity

Inadequately planned transport systems result to traffic congestion, a challenge that has for long been a thorn in Dar es Salaam, the city most affected in Tanzania. Although traffic congestion has been a major concern in Dar es Salaam, marked reluctance has been noticed in taking measures towards a lasting solution thus, it is of diminutive surprise that limited studies and documentations on the same are in existence. Therefore, this study assesses traffic congestion in Dar es Salaam and particularly its implications for workers’ productivity. Travel time and productivity indexes were established from a sample of 96 workers who used public transport along Morogoro and Mandela Roads. Travel time index (TTI) is the ratio of the average travel time during peak period to the travel time during off-peak period. Findings reveal that TTI was 2.19. Workers spent about 2 times of the average commuting time to work and 3 times of the same commuting from work to their various residences. About 2.5 hours were lost on traffic jam per day and that people worked 1.4 times less than the required time due to traffic congestion. It was further established that in 10 working days, almost 3 days were lost to traffic congestion. Since there are ongoing efforts to improve the transport system through the Bus Rapid Transit (BRT) project, it remains to be seen as to what extent traffic congestion will be reduced. In either case, this study provides a benchmark for comparisons.