The purpose of this study is to evaluate potential travel time impacts of the implementation of exclusive heavy-vehicle lanes on the Interstate Highway 35 (IH 35) corridor, in the Austin metropolitan area. The analysis considers heavy vehicles (trucks) and non-heavy vehicles (cars) as separate system elements and as an integrated system. The study modeled traffic operations on IH 35, during the AM and PM peak hours, under two traffic scenarios, Existing and Inside Truck-Only Lanes using the software VISSIM 5.4. The limits of the study are FM 1431 in Round Rock, on the north, and SH 45 near Buda, on the south. The Existing scenario modeled traffic operations under current IH 35 geometric conditions and traffic control rules, in which trucks are prohibited from the inside lane and cars are allowed in all lanes. The Inside Truck-Only Lanes scenario modeled traffic operations under the assumption that trucks are restricted to the inside lane only and cars are prohibited from the inside lane. Travel times across the study area corridor were measured in the models to compare the performance of the Inside Truck-Only Lanes scenario relative to the Existing scenario. / text

Thesis (Ph.D.)--University of Texas at Arlington, 2009.

abstract: Managed Lanes (MLs) have been increasingly advocated as a way to reduce congestion. This study provides an innovative new tolling strategy for MLs called the travel time refund (TTR). The TTR is an “insurance” that ensures the ML user will arrive to their destination within a specified travel time savings, at an additional fee to the toll. If the user fails to arrive to their destination, the user is refunded the toll amount. To gauge interest in the TTR, a stated preference survey was developed and distributed throughout the Phoenix-metropolitan area. Over 2,200 responses were gathered with about 805 being completed. Exploratory data analysis of the data included a descriptive analysis regarding individual and household demographic variables, HOV usage and satisfaction levels, HOT usage and interests, and TTR interests. Cross-tabulation analysis is further conducted to examine trends and correlations between variables, if any. Because most survey takers were in Arizona, the majority (53%) of respondents were unfamiliar with HOT lanes and their practices. This may have had an impact on the interest in the TTR, although it was not apparent when looking at the cross-tabulation between HOT knowledge and TTR interest. The concept of the HOT lane and “paying to travel” itself may have turned people away from the TTR option. Therefore, similar surveys implementing new HOT pricing strategies should be deployed where current HOT practices are already in existence. Moreover, introducing the TTR concept to current HOT users may also receive valuable feedback in its future deployment. Further analysis will include the weighting of data to account for sample bias, an exploration of the stated preference scenarios to determine what factors were significant in peoples’ choices, and a predictive model of those choices based on demographic information. / Dissertation/Thesis / Masters Thesis Civil and Environmental Engineering 2015

As bicycle transportation has increased, especially among commuters, so have the types of bicycle infrastructure facilities increased. This report focuses on the application of several of these innovative bicycle infrastructure treatments in three different scenarios: shared-lane facilities, bicycle-specific facilities, and high-conflict area treatments. The focus treatments include the sharrow, Sharrow Bicycle Priority Lane, Green Bicycle Priority Lane, Bicycles May Use Full Lane sign, green bike lane, bike-box, green lane in a conflict area, and elephant's footprint markings. The goal of this report is to gather how well bicyclists understand their meaning, how they would use each, and which treatments are most preferred among bicyclists. Data for this study was gathered in the form of an online survey administered to 1000 bicyclists of varying levels and purposes from different regions of the country. The survey gathers general rider characteristics, asks how each bicyclist would use each treatment in different traffic speed and volume scenarios, and finally each respondent rates each of the treatments in order of preference. Using the survey results, the effectiveness of each treatment is analyzed in detail by different population segments of those surveyed. Bicyclist riding characteristics and route choice factors are also examined in detail to better understand the sampled population of riders. The results are discussed and conclusions to the effectiveness of each treatment are made.

Thesis (MScEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Capacity waste happens when right-turn vehicles have right-of-way during a separate right-turn phase and lanes (e.g., through lanes) of the same approach of the intersection cannot discharge vehicles during that green phase. Right-turn traffic consumes the capacity which otherwise could be provided to through traffic movements at an at-grade signalized intersection. Therefore, it is widely considered that it would lower intersection capacity and increase total delay (Lin, Machemehl, Lee & Herman, 1984). The pre-signal strategy proposed in this research is specifically designed to improve this problem. The following aspects of this strategy were studied in this research, - Capacity benefits of this strategy, - Relationships between the capacity and the length of sorting area (the area between the two signals), - Signal timing of both main signal and pre-signal, - Clearance time of the sorting area, - Main signal phasing options - Signal coordination between the main signal and the pre-signal, - Utilization of the sorting area, and - Pre-signal strategy performance in a simulated environment. The results of this study showed that right-turn movement benefits significantly from this pre-signal strategy. For example, right-turn capacity can be doubled if a presignal is installed on one through lane of an approach with one right-turn lane. It was also found, the maximum approach capacity benefit is not affected significantly by the length of the sorting area for a given green period. The optimal green time and the available pre-signal green time for right-turn movement were also derived in this research. Different main signal phasing options were studied and compared. Phasing options which fit the proposed pre-signal strategy were found. Recommended values for right-turn green time of both signals were given based on different lengths of sorting area. The case study, which compared the performance of some critical movements at the intersection with and without the proposed pre-signal system, confirms the results concluded in this study. A potential problem with this strategy when applied at a real intersection is that it may confuse drivers. Drivers need to be educated and will need time to get familiar with this signal control method. / AFRIKAANSE OPSOMMING: Beskermde regsdraaifases vir verkeer by gelykvlak seinbeheerde kruisings gebruik die kapasiteit wat benut kon word deur deurbewegings. Dit verlaag interseksie kapasiteit en totale oponthoud verhoog. Die voorseinstrategie wat in die navorsing studie voorgestel word is spesifiek ontwikkel om die probleem op te los of te verminder. Die volgende aspekte van die strategie is ondersoek in die navorsingsstudie: - Kapasiteitsvoordele van die strategie. - Die verhouding tussen die kapasiteit en die lengte van die sorteringsarea (die area tussen die twee seine). - Seintydstoedeling van beide die hoofseinfase en die voorseinfase. - Ontruimingstyd van die stoorarea. - Hoofseinfaseopsies. - Seinkoordenasie tussen die hoofsein en die voorsein. - Benutting van die sorterings area, en - Voorseinstrategieprestasie in ‘n gesimuleerde omgewing. Die resultate bewys dat die regsdraaibeweging grootliks bevoordeel word nadat die voorseinstrategie ingestel is. Byvoorbeeld, regsdraaikapasiteit kan verdubbel word as ‘n voorseinfase ingestel word op een van die deurlane tesame met ‘n enkele regsdraailaan. Daar is ook gevind dat die kapasiteit nie grootliks beinvloed word deur die lengte van die stoorgebied nie. Die optimale groentyd en die beskikbare voorsein groen tyd vir die regsdraaibeweging is ook afgelei in die navorsing. Verskillende hoofseinfaseopsies is bestudeer en vergelyk. Faseringsopsies vir die voorgestelde voorseinstrategie is gevind. Voorgestelde waardes vir regsdraaigroentyd van voorseine en hoofseine is bereken om kapasiteit te verbeter, gebasseer op verskillende lengtes van die stoorarea. Die gevallestudie wat die prestasie op ‘n aanloop met en sonder die voogestelde voorseinstrategie vergelyk, bewys resultate wat ooreenstem met die bevindinge in die studie. Die verwagte probleem met die voorseinstrategie, wanneer dit ingestel word by ‘n werklike interseksie, is verwarring van die bestuurders. Bestuurders sal opgevoed moet word en sal tyd nodig hê om gewoond te raak aan die voorseinmetode.

The objective of this study was to provide an estimate of the protected dual left turn saturation flow rates in the Tucson area. The data were collected from dual left turn lanes at six intersections. The headway times were measured in order to calculate the saturation flow rates at each of the study sites. Observations were made at four intersections with left turn protected and at two intersections with permitted plus protected left turns. Saturation flow was measured from the third to the last vehicle in the queue. Observations were made during the time of expected peak traffic flow. A stop watch was used to measure the time intervals to the nearest tenth of a second. The saturation flow rates were then calculated and varied from 1621 to 2017 Vehicles Per Hour of Green Per Lane (VPHGL) for the inside lane to 1737 to 1802 VPHGL in the outside lane.

A Master’s research project submitted to the Faculty of Science, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Science in GIS and Remote Sensing. Johannesburg, 2017. / Recent initiatives by the city of Johannesburg to increase non-motorised transport through the installation of bicycle infrastructure were conducted without consulting the cycling preferences of the public. This study distributed a cycling preference survey, achieving fair reliability using the weighted Kappa statistic, in which potential users indicated the most important spatial factors for ideal cycling routes through Likert-scale answers. Importance rankings derived by Likert sums were combined with variability-explaining rankings derived by modified principal component analysis using polychoric correlation coefficients to produce a final list of retained spatial variables. These variables were quantified using secondary spatial data sets which were dichotomized into Boolean operators for network attributes in ArcGIS Network Analyst. The solved routes using the spatial factors derived by survey respondents were significantly different from the simple shortest-path routes between pre-defined origin and destination nodes. Shortcomings in the directness of the solved routes qualify their use as an initial step for non-motorised transport planning rather than a strict, unmodifiable route for bicycle lanes. Further experimentation with higher quality spatial data, custom routing algorithms, and a larger survey population may yield improved results in the future. The incorporation of local cyclists and future cyclists are a key factor in bicycle route design that should be included in non-motorised transport planning. / LG2018

Disagreements regarding to what degree right-turn lanes improve or worsen the safety of intersections and driveways provided the motivation and the need for this study. The objectives of this study were to: a) carry out an in-depth study to determine the safety impacts of right-turn movements in different contexts, and b) develop safety-based volume warrants for right-turn lanes if safety indeed improves. Lack of adequate study on the applicability of past warrants and guidelines for the specific context of right-turn movements made from major uncontrolled approaches at unsignalized intersections, and particularly driveways, on two-lane roadways provided the scope for this study. Five-year historical data of statewide traffic crashes reported on Minnesota's twolane trunk highways were analyzed using binary/multinomial logistic regressions. Conflicts due to right turns were analyzed by fitting least squares conflict prediction models based on the data obtained from field surveys and traffic simulations. The safety impacts of rightturn lanes were determined through crash-conflict relationships, crash injury severity, and crash and construction costs. The study found that the probabilities of right-turn movement related crash ranged from 1.6 to 17.2% at intersections and from 7.8 to 38.7% at driveways. Rear-end, samedirection- sideswipe, right-angle and right-turn crash types constituted 96% of right-turn movement related crashes. Rear-end crash probabilities varied from 13.7 to 46.4% at approaches with right-turn lanes and from 37.9 to 76.9% otherwise. The ratios of rearend/ same-direction-sideswipe crashes to conflicts were 0.759 x 10-6 at approaches with right-turn lanes and 1.547 x 10-6 otherwise. iv Overall, right-turn lanes reduced right-turn movement related crash occurrences and conflicts by 85% and 80%, respectively. Right-turn lanes also reduced crash injury severity, hence, reducing the economic cost by 26%. Safety benefits, in dollars, realized with the use of right-turn lanes at driveways were 29% and 7% higher compared to those at intersections at low and high speed conditions respectively for similar traffic conditions. Depending on roadway conditions, interest rate and construction costs, the safety-based volume thresholds ranged from 3 to 200 right turns per hour during the design hour at intersection approaches, and from 2 to 175 right turns at driveway approaches. / Civil and Environmental Engineering / College of Engineering

Thesis (M.A. in City and Regional Planning)--University of California, Berkeley, Fall 2005. / Title from PDF title page (viewed Dec. 13, 2007). "Fall 2005." Includes bibliographical references (p. 81-87).

The growing number of trucks traveling on freeways has caused more traffic congestion and increased the likelihood of truck-related crashes. Many transportation agencies are considering a new concept of truck-only toll (TOT) lanes to provide a more efficient and safer freight transportation system. This research develops a methodology for identifying candidate TOT lanes in the freeway system. The modeling of TOT lanes in different geographic applications includes individual TOT corridors, a regional TOT network, and a statewide TOT network. The criteria employed in a geographic information system (GIS)-based screening process to determine feasible TOT corridors and their boundaries/extents include: freeway level of service, truck volumes, truck percentage of total freeway flow, truck-related crashes, and truckers willingness to pay. The research also presents the process for determining optimum toll rates for TOT lanes. Furthermore, this research addresses issues of assessing the engineering design of TOT lane placement and the performance measures of using either mandatory or voluntary TOT lanes. This research also examines freeway performance under two scenarios -- adding general purpose lanes or building TOT lanes with both mandatory and voluntary use. Finally, this research addresses the strategies for critical issues associated with the planning, design, and operation of TOT lanes and presents TOT planning guidance.