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| 2. |
- Farah, Haneen
(författare)
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Age and Gender Differences in Overtaking Maneuvers on Two-Lane Rural Highways
- 2011
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Ingår i: Transportation Research Record. - : SAGE Publications. - 0361-1981 .- 2169-4052. ; :2248, s. 30-36
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Tidskriftsartikel (refereegranskat)abstract
- For decades researchers have been pointing out significant differences in the driving behavior between young and old and between male and female drivers. There are many studies concerning age and gender differences in risk perception, traffic accident involvement, traffic violations, alcohol consumption, and risky driving. However, little effort has been focused on studying the behavioral differences in overtaking maneuvers on two-lane highways. A considerable percentage of the fatal accidents on two-lane highways is directly related to overtaking maneuvers. Therefore, the main focus of this study is to understand better the overtaking behavior of different drivers classified by their age and gender. Data on the overtaking behavior of 100 drivers were collected with an interactive driving simulator. Several scenarios of two-lane rural highways with different geometric and traffic conditions were developed. The results show interesting and significant differences in the overtaking behavior of drivers depending on their age and gender. These differences are mainly in the frequency of overtaking maneuvers, overtaking time duration, following distances, critical overtaking gaps, and desired driving speeds. Geometric and traffic conditions were also found to have a significant impact on drivers' overtaking behavior. The findings of this study contribute to the understanding of the overtaking behavior of different groups of drivers and thus have implications for road safety intervention programs and the development of effective risk reduction strategies adapted and targeted for different age and gender groups.
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| 3. |
- Farah, Haneen, et al.
(författare)
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Do cooperative systems make drivers' car-following behavior safer?
- 2014
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Ingår i: Transportation Research Part C. - : Elsevier BV. - 0968-090X .- 1879-2359. ; 41, s. 61-72
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Tidskriftsartikel (refereegranskat)abstract
- The main goal of in-vehicle technologies and co-operative services is to reduce congestion and increase traffic safety. This is achieved by alerting drivers on risky traffic conditions ahead of them and by exchanging traffic and safety related information for the particular road segment with nearby vehicles. Road capacity, level of service, safety, and air pollution are impacted to a large extent by car-following behavior of drivers. Car-following behavior is an essential component of micro-simulation models. This paper investigates the impact of an infrastructure-to-vehicle (I2V) co-operative system on drivers' car-following behavior. Test drivers in this experiment drove an instrumented vehicle with and without the system. Collected trajectory data of the subject vehicle and the vehicle in front, as well as socio-demographic characteristics of the test drivers were used to estimate car-following models capturing their driving behavior with and without the I2V system. The results show that the co-operative system harmonized the behavior of drivers and reduced the range of acceleration and deceleration differences among them. The observed impact of the system was largest on the older group of drivers.
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| 4. |
- Farah, Haneen, et al.
(författare)
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Drivers' Irrationality in Evaluating Risks on Two-Lane Highways
- 2012
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Ingår i: Journal of Transportation Safety and Security. - : Informa UK Limited. - 1943-9962 .- 1943-9970. ; 4:1, s. 67-82
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Tidskriftsartikel (refereegranskat)abstract
- Head-on collisions on two-lane rural highways might result from failed passing maneuvers. This paper investigates the hypothesis that drivers do not always estimate the required passing gap correctly, and their decision to overtake is made under a particular, even if small, probability that a crash will occur; this is the associated risk. The research investigates drivers’ irrationality in evaluating the risks of different passing gaps and, develops a risk-taking measure. This measure provides a tool for classifying drivers into different groups: risky drivers, partially cautious, and cautious drivers. A comparison of the socio-demographic averages, driving style, and crash history parameters for these groups showed significant differences.The measure developed can be used for risk evaluation and as a measure of safety. It further provides a tool for classifying drivers into groups based on their risk-taking characteristics. This is particularly useful for safety education programs.
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| 5. |
- Farah, Haneen, et al.
(författare)
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Evaluation of the effect of cooperative infrastructure-to-vehicle systems on driver behavior
- 2012
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Ingår i: Transportation Research Part C. - : Elsevier BV. - 0968-090X .- 1879-2359. ; 21:1, s. 42-56
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Tidskriftsartikel (refereegranskat)abstract
- In-vehicle technologies and co-operative services have potential to ease congestion problems and improve traffic safety. This paper investigates the impact of infrastructure-to-vehicle co-operative systems, case of CO-OPerative SystEms for Intelligent Road Safety (COOPERS), on driver behavior. Thirty-five test drivers drove an instrumented vehicle, twice, with and without the system. Data related to driving behavior, physiological measurements, and user acceptance was collected. A macro-level approach was used to evaluate the potential impact of such systems on driver behavior and traffic safety. The results in terms of speeds, following gaps, and physiological measurements indicate a positive impact. Furthermore, drivers' opinions show that the system is in general acceptable and useful.
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| 6. |
- Farah, Haneen, et al.
(författare)
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Impact of Cooperative Systems on Drivers' Car-Following Behavior
- 2012
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Ingår i: TRB 91st Annual Meeting Compendium of Papers.
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Konferensbidrag (refereegranskat)abstract
- In-vehicle technologies and co-operative services are designed to ultimately reduce congestion and increase traffic safety. This paper investigates the impact of an infrastructure-to-vehicle co-operative system on drivers’ car-following behavior. Car following behavior, which describes the behavior of a vehicle while following the vehicle in front of it, has a significant impact on traffic performance, safety, and air pollution. In addition, it is an essential component of microsimulation models. Twenty nine test drivers drove an instrumented vehicle twice with and without the system. Trajectory data of each vehicle and the vehicle in front were collected. Car-following models were estimated for both cases, with and without the system, and the results of the two models were compared. The results show that co-operative systems have a positive impact on drivers’ car-following behavior. The system harmonizes the driving behavior of drivers and reduces the range of acceleration and deceleration differences among them. The impact of the system is larger on older drivers compared to younger drivers.
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| 7. |
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| 8. |
- Farah, Haneen
(författare)
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Modeling drivers' passing duration and distance in a virtual environment
- 2013
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Ingår i: IATSS Research. - : Elsevier BV. - 0386-1112. ; 37:1, s. 61-67
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Tidskriftsartikel (refereegranskat)abstract
- In many countries two-lane rural highways constitute a large proportion of the road network. One of the most fatal crash types is head-on collisions. Some of these head-on collisions are caused by failed passing maneuvers, when a driver does not succeed to complete the pass safely.Detailed observation of drivers' passing behavior in reality is difficult and complex. This study uses a driving simulator to collect detailed data on drivers' passing behavior. Using this data, empirical models explaining passing duration and distance were developed and estimated. These models take into account the impact of the traffic conditions, geometric design, and drivers' socio-demographic characteristics.The results revealed that the passing duration and distance of older drivers are significantly higher than younger drivers. The passing duration and distance are significantly affected by the traffic related variables of the subject, front, and opposing vehicles. The duration and passing distance increase when drivers initiate the passing maneuvers from a larger following distance from the front vehicle. Driver gender, road curvature, and types of front and opposing vehicles were not found to have a statistically significant impact on the passing duration and distance.The time that takes the driver to arrive to the critical position, or the point of no return, from the moment of start passing is equal to 41.7% of the time needed to complete the passing maneuver, higher compared to the value suggested by AASHTO (33%). This has important implications on safety.The main contribution of this paper is in the empirical models developed for passing duration and distance which highlights the factors that affect drivers' passing behavior and can be used to enhance the passing models in simulation programs.
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| 9. |
- Farah, Haneen, et al.
(författare)
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Passing behavior on two-lane highways
- 2010
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Ingår i: Transportation Research Part F. - : Elsevier BV. - 1369-8478 .- 1873-5517. ; 13:6, s. 355-364
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Tidskriftsartikel (refereegranskat)abstract
- Two-lane highways make up a substantial proportion of the road network in most of the world. Passing is among the most significant driving behaviors on two-lane highways. It substantially impacts the highway performance. Despite the importance of the problem, few studies attempted to model passing behavior. In this research, a model that attempts to capture both drivers' desire to pass and their gap acceptance decisions to complete a desired passing maneuver is developed and estimated using data on passing maneuvers collected with a driving simulator. Sixteen different scenarios were used in the experiment in order to capture the impact of factors related to the various vehicles involved, the road geometry and the driver characteristics in the model. A passing behavior model is developed that includes choices in two levels: the desire to pass and the decision whether or not to accept an available passing gap. The probability to complete a passing maneuver is modeled as the product of the probabilities of a positive decision on both these choices. The estimation results show that modeling the drivers' desire to pass the vehicle in front has a statistically significant contribution in explaining their passing behavior. The two sub-models incorporate variables that capture the impact of the attributes of the specific passing gap that the driver evaluates and the relevant vehicles, the geometric characteristics of the road section and the driver characteristics and account for unobserved heterogeneity in the driver population.
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| 10. |
- Koutsopoulos, Haris N., et al.
(författare)
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Latent Class Model for Car Following Behavior
- 2012
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Ingår i: Transportation Research Part B. - : Elsevier BV. - 0191-2615 .- 1879-2367. ; 46:5, s. 563-578
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Tidskriftsartikel (refereegranskat)abstract
- Car-following behavior, which describes the behavior of a vehicle while following the vehicle in front of it, has a significant impact on traffic performance, safety, and air pollution. In addition, car-following is an essential component of micro-simulation models. Over the last decade the use of microscopic simulation models as a tool for investigating traffic systems, ITS applications, and emission impacts, is becoming increasingly popular. The paper presents a flexible framework for modeling car-following behavior that relaxes some limitations and assumptions of the most commonly used car following models. The proposed approach recognizes different regimes in driving such as car-following, free-flow, emergency stopping, and incorporates different decisions in each regime, such as acceleration, deceleration, and do-nothing depending on the situation. A case study using NGSIM vehicle trajectory data is used to illustrate the proposed model structure. Statistical tests suggest that the model performs better than previous models.
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| 11. |
- Mwesige, Godfrey, 1978-, et al.
(författare)
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Capacity and Safety of Passing Zones on Two-Lane Rural Highways : A Review of Theory and Practice
- 2014
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Ingår i: Journal of Traffic and Logistics Engineering. - : EJournal Publishing. - 2301-3680. ; 2:2
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Tidskriftsartikel (refereegranskat)abstract
- Passing zones are primary operational features of two-lane rural highways where fast vehicles pass slow vehicles using a lane reserved for traffic in opposing direction. The operation of these zones has an effect on the overall safety of two-lane rural highways especially when passing opportunities reduce considerably at higher flows. This paper presents a review on capacity and safety of passing zones on two-lane rural highways. Despite stated importance of passing zones to the operational performance of two-lane rural highways, passing zone capacity has not been estimated and its impact on safety is still not known. Safety evaluations mainly compare adequacy of design and marking passing sight distances to complete passing maneuvers as well as parameters derived from the passing process namely; passing duration, speed difference between passing and passed vehicles, and clearance between passing and opposing vehicle at the end of the maneuver. There is need for further research to address gaps in current capacity and safety evaluation methods of two-lane rural highways with focus on; (a) development of robust passing rate models for individual passing zones based on geometric, environmental and traffic factors, (b) estimation of passing zone capacity, (c) development of criteria to evaluate capacity and safety of passing zones for use by policy makers, planners and transportation engineers and (d) application of passing zone capacity to evaluate rural highway sections with several passing zones.
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| 12. |
- Silvano, Ary P., 1975-
(författare)
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Impacts of Speed Limits and Information Systems on Speed Choice from a Safety Perspective.
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Driving a vehicle is considered a demanding task in a complex dynamic environment. For instance, driving a vehicle on urban roads, where motorized vehicles meet vulnerable road users (VRUs) creates a multifaceted environment with difficult trade-offs and interactions. Additionally, in-vehicle technology developments are being introduced to ease drivers with the driving task. However, these developments are changing “traditional” driving increasing drivers’ response in terms of information processing, thus making the driving task more demanding in some respects. Therefore, the aim of the present research is to further investigate drivers’ speed choice under varying traffic management regulations and in-vehicle warning systems.
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| 13. |
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| 14. |
- Toledo, Tomer, et al.
(författare)
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Alternative Definitions of Passing Critical Gaps
- 2011
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Ingår i: Transportation Research Record. - : SAGE Publications. - 0361-1981 .- 2169-4052. ; :2260, s. 76-82
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Tidskriftsartikel (refereegranskat)abstract
- A substantial proportion of the road network in most countries consists of two-lane highways. Available gaps for passing are a fundamental element in the operation of such highways. Providing passing opportunities is important for reducing the formation of vehicle platoons in the traffic flow, increasing the level of service, and improving safety. Passing opportunities also affect fuel consumption and emissions. Despite the importance of passing on two-lane highways, few studies have focused on exploring passing gap definitions when modeling passing behavior. Research was done to investigate various definitions of passing gaps, and these definitions were used to develop passing gap acceptance models. Data on passing maneuvers collected with a driving simulator were used to develop and calibrate three models. The generic structure of these models was composed of the drivers' desire to pass and their gap acceptance decisions. The impact of traffic characteristics, road geometry, and driver characteristics was included in these models. The results show that the passing gap definition has a significant impact on the models' ability to explain passing behavior. Moreover, the estimation results show that modeling a driver's desire to pass the vehicle ahead has a statistically significant contribution in explaining passing behavior. Variables that capture the impact of the traffic conditions, geometric characteristics of the road section, driver characteristics, and the unobserved heterogeneity in the driver population were found to have a significant impact on drivers' desire to pass and their gap acceptance decisions.
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