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An accurate short-term traffic forecasting model serves as an integral part to enhance the efficiency of vehicle rerouting and traffic light control strategies. The information exchange (pheromone) behavior of ants has been applied to forecast traffic conditions in existing pheromone models. These models were developed to forecast congestion on roads with signalized intersections by considering only green and red phases. Motivated by this issue, three short-term traffic forecasting models are proposed: (i) Extended Pheromone Model (EPM), (ii) Extended Pheromone Model with epsilon-Support Vector Regression (ε SVR-EPM), and (iii) Extended Pheromone Model with Artificial Neural Network and Particle Swarm Optimization (ANNPSO-EPM). It is worth noticing that EPM is an algorithmic model whereas the other two are machine learning models. In all proposed models, a new color pheromone concept is proposed with two significant contributions. First, the color pheromone concept is developed to capture stochastic traffic conditions on the roads with non-signalized intersections. Second, the proposed concept is further extended to include all three color phases (red, yellow and green) to forecast dynamic changing traffic behaviors for roads with signalized intersections. The proposed color pheromone concept in EPM, ε SVR-EPM, and ANNPSO-EPM is different from the existing models as it dynamically switches its computation techniques based on traffic light phases. All three proposed models can be realized through a Pheromone-based Multi-Agent System composed of Vehicle Agents and Intersection Agents coordinating locally with one another To promote practicality, Singapore City Hall map is employed in a microscopic simulator of Simulation of Urban Mobility (SUMO), showing that all proposed models outperform the other existing pheromone models. [ABSTRACT FROM AUTHOR]

This study analysed the feasibility of a bike-sharing programme in Singapore based on a case study in the Jurong Lake district. Data were collected using a two-stage perception survey to gather the public's general awareness and opinions about bike sharing and followed by estimating the likely take-up rate of bike sharing. The results showed that bike-sharing schemes would be suitable around mass rapid transit stations and low rental costs would encourage bike sharing. Finally, a distance-based mode-choice model was established for four scenarios (morning peak and good weather, morning peak and bad weather, evening peak and good weather and evening peak and bad weather), focusing on walking, bike sharing and taking a bus. Weather could have an obvious impact on the frequency of bike sharing. [ABSTRACT FROM AUTHOR]

This paper presents the development and validation of a driving simulator for ramp traffic control on expressways using a traffic simulator and control (TSC). The TSC consists of two main components: car-following model (CFM), and traffic controller (TC). The CFM simulates the car-following behavior and delivers aggregated traffic parameters to the TC to derive control actions. The CFM and TC are harmonized and integrated in a close-loop control manner, where the effects of the control by the TC are fed-back as inputs for the CFM in real-time applications. Although the following behavior of individual vehicles is simulated, the aggregated outputs such as average speed and flow rate from the model are the parameters of interest. For simplicity in the model development and validation and to capture lane-changing effects, the traffic in the multi-lane expressway where the data were obtained was equivalently represented as a single-lane system. The validation of the CFM was performed at macroscopic level where aggregated outputs from the model were compared to observed data in a segment of the Pan Island Expressway of Singapore under various traffic conditions. The result shows that the simulated speed is not significantly different from the actual speed at 5% significance level, and the aggregated flow rate discrepancies fall in a small range, from 2.21% to 3.15%. This shows that the TSC model is a reliable model for traffic simulation and control applications. • Traffic simulation models are useful tools in studying traffic systems. • Car-following model is key building block of microscopic traffic simulation models. • Validation is most important in developing microscopic traffic simulation models. • By studying statistical properties, CFMs explain behavior of macroscopic systems. • TSC model is a trustworthy simulator for traffic management and control. [ABSTRACT FROM AUTHOR]

Singapore, facing a land scarcity issue, has been continuously looking for sustainable urban transport solutions to facilitate effective movement within the island nation. With the recent population projection of 6·9 million and the unprecedented national age shift (towards ageing) by 2030, investing more on non-motorised transport (NMT), namely walking and cycling, may be a workable solution. The first part of the paper focuses on assessing the first/last mile trips connecting to rail transit stations and evaluating NMT as a viable solution in the Singapore context. Engineering and behavioural studies aimed at providing adequate NMT infrastructure to the increasing demand of users are discussed next. Safety, accessibility and capacity of the NMT network are assessed by the use of the safety and accessibility index. Current key research findings (such as pedestrian shed, NMT push and pull factors and route choice models) are showcased. [ABSTRACT FROM AUTHOR]

For large-scale traffic assignment applications, mesoscopic simulation has more advantages than microscopic and macroscopic simulation because it has a well-designed tradeoff between the level of details and the running efficiency. Currently, the time complexity of time-stepped mesoscopic supply framework is linear to the number of vehicles on the lanes. To simulate an entire city the computation cost is often practically unacceptable. To tackle this problem, we propose a novel approach named 'Entry Time based Supply Framework (ETSF)' to improve the performance of mesoscopic applications. The main idea is that ETSF updates the 'entry_time_to_pass' and 'entry_time_to_queue' parameters of each lane to compute the moving/queuing parts of link/lane vehicles, which means reducing the time complexity of the number of vehicles passing the lanes. To validate this innovation of ETSF, a series of experiments were carried out on a sub-network of Singapore and the outcomes show that ETSF is less sensitive with the demand level (or the total number of vehicles) and greatly improves the performance, especially when simulating congested traffic scenarios. In the global research framework of mesoscopic traffic simulations, ETSF offers an innovative and time-efficient way to model traffic dynamics on links. [ABSTRACT FROM AUTHOR]

Highlights: [•] Road traffic accidents that occurred on three expressway tunnels are studied. [•] Accident rates are found to be highest in the transition zones. [•] Accident rates are much higher in tunnel entry as compared to exit. [•] Spatial differences in accident rates can be attributed to multivehicle crashes. [•] Casualty likelihood is found to be higher in single vehicle crashes. [Copyright &y& Elsevier]

Abstract: Motorcyclists are the most crash-prone road-user group in many Asian countries including Singapore; however, factors influencing motorcycle crashes are still not well understood. This study examines the effects of various roadway characteristics, traffic control measures and environmental factors on motorcycle crashes at different location types including expressways and intersections. Using techniques of categorical data analysis, this study has developed a set of log-linear models to investigate multi-vehicle motorcycle crashes in Singapore. Motorcycle crash risks in different circumstances have been calculated after controlling for the exposure estimated by the induced exposure technique. Results show that night-time influence increases crash risks of motorcycles particularly during merging and diverging manoeuvres on expressways, and turning manoeuvres at intersections. Riders appear to exercise more care while riding on wet road surfaces particularly during night. Many hazardous interactions at intersections tend to be related to the failure of drivers to notice a motorcycle as well as to judge correctly the speed/distance of an oncoming motorcycle. Road side conflicts due to stopping/waiting vehicles and interactions with opposing traffic on undivided roads have been found to be as detrimental factors on motorcycle safety along arterial, main and local roads away from intersections. Based on the findings of this study, several targeted countermeasures in the form of legislations, rider training, and safety awareness programmes have been recommended. [Copyright &y& Elsevier]

Navigational collisions are one of the major safety concerns for many seaports. Despite the extent of work recently done on collision risk analysis in port waters, little is known about the influential factors of the risk. This paper develops a technique for modelling collision risks in port waterways in order to examine the associations between the risks and the geometric, traffic, and regulatory control characteristics of waterways. A binomial logistic model, which accounts for the correlations in the risks of a particular fairway at different time periods, is derived from traffic conflicts and calibrated for the Singapore port fairways. Results show that the fairways attached to shoreline, traffic intersection and international fairway attribute higher risks, whereas those attached to confined water and local fairway possess lower risks. Higher risks are also found in the fairways featuring higher degree of bend, lower depth of water, higher numbers of cardinal and isolated danger marks, higher density of moving ships and lower operating speed. The risks are also found to be higher at night. [ABSTRACT FROM PUBLISHER]

There are two problems associated with contraflow operations, namely, the lane configuration problem and the scheduling problem. The former determines the optimal lane reversing scheme for the operation while the latter decides the start time and the duration of contraflow. In this study, both problems are modelled under one bi-level programming model. The upper level problem gives the optimal lane configuration and schedule by minimising the total travel time of the study area, while the lower level is a traffic simulation model that can capture the response of drivers towards the network changes. A hybrid metaheuristic-traffic simulation methodology is suggested to solve the proposed model. An illustrative case study of Singapore arterial network is adopted as an example to test the effectiveness of the proposed model and algorithm. Results show that by considering these problems simultaneously, an overall optimal solution can be obtained compared with solving the problems individually. [ABSTRACT FROM AUTHOR]

Driver performance in responding to the green-amber-red signal change was studied based on a sample of 2316 last crossing and first stopping vehicles collected by unobtrusive observations at 10 junction approaches in Singapore. Two schemes, a speed-distance diagram (S-D) and an acceleration-deceleration (A-D) diagram, were used to demarcate the driving situations; the driver actions, as revealed outcomes of driver decision-making, were mapped onto these diagrams. The speed-distance diagram can give some indication on what a driver would possibly do. The more complicated acceleration-deceleration diagram is useful for diagnosing the appropriateness of the driver actions. An application of the A-D diagram was demonstrated, and several situations prone to red-running were noted. [ABSTRACT FROM AUTHOR]

Most automatic incident detection algorithms were successfully developed using loop-detector-based traffic measurements collected from their own localities. But their detection performances were not satisfactory when applied on data collected using a video-based detector system. The video-based detector system is gaining popularity as it was reported to be cost-effective, less prone to damage compared to loop detectors embedded in road pavement, and possesses surveillance capability. It is able to provide the homogeneity of traffic measurements with greater reliability in non-incident situations. In this study, a simple detection rule was used to develop algorithms that use video-based data for detecting lane-blocking incidents. A set of 96 incidents from Singapore's Central Expressway was used for calibrating these algorithms, with another 64 incidents for validation. Two single-station algorithms, named dual-variable (DV) and flow-based DV algorithms were developed. They have similar detection logic, but the latter includes a pre-incident traffic flow condition in its detection framework. On average, the flow-based DV algorithm outperformed the DV algorithm, and both proved to be effective techniques when compared to some existing loop-detector-based algorithms. [ABSTRACT FROM AUTHOR]

In heavy traffic flow conditions, vehicles have limited manouverability which affects the magnitude of response to incident-induced traffic disturbances and how fast changes in these traffic variables can signal the occurrence of an incident. Such characteristics are usually used to formulate a loop-based algorithm. A recent study reported that some existing algorithms were not able to maintain a desired level of effectiveness when these algorithms were used to detect incidents with a video-based detector system. Two new video-based automatic incident detection algorithms, the INdividual Detection Evaluation (INDE) and COmbined Detection Evaluation (CODE) algorithms were, therefore, developed for the detection of lane-blocking incidents in heavy traffic flow conditions using the Central Expressway in Singapore as a case study. The algorithms detect incident-induced traffic speed and occupancy disturbances differently: INDE processes information at each individual detector station and CODE processes information at two adjacent detector stations. Both algorithms outperformed existing algorithms commonly used in incident management systems. Of these algorithms, the INDE algorithm raised fewer false alarms and gave slightly faster incident warnings. However, its performance was relatively less consistent when applied to a validation database. [ABSTRACT FROM AUTHOR]

The congestion charging schemes in London and Singapore are compared and assessed in the light of guidelines set out in the Smeed Report, published by the UK Ministry of Transport in 1964, and their performance in reducing congestion and raising net revenue. The aim is to draw lessons for other towns and cities considering the introduction of congestion charging. One important result from Electronic Road Pricing in Singapore is that a per‐entry charge is more effective at reducing congestion than a per‐day charge. It is concluded that although Electronic Road Pricing in Singapore is more in line with the desirable properties outlined in the Smeed Report, both schemes are part of a wider package of transport policies, and that is probably the most important reason for their success. The main lesson for other towns and cities around the world considering the possibility of introducing congestion charging is that any such scheme ought to be accompanied by complementary measures that will provide motorists with a valid alternative to the car. [ABSTRACT FROM AUTHOR]

Facing traffic congestion in the Central Business District and enormous demands on scarce land resources by the growing number of motor vehicles, Singapore, a small island city-state the size of Seattle, embarked on a bold decision to reduce road congestion by implementing the famous Area Licensing Scheme in 1975. This was a manual system of tolls for multiple entries into the Restricted Zone. While achieving the intended effect of cutting down on the volume of vehicular traffic in the Restricted Zone, the authors (and others) found that the problem of congestion had merely shifted in time and place. Many changes were implemented, including shoulder pricing (reduced tolls before and after the peak period) to even out traffic flows in 1994, and the Weekend Car Scheme (1991) and Off Peak Car Scheme (1994) to encourage people to use the roads during off-peak hours. The Road Pricing Scheme was introduced in 1995 on a congested highway to familiarize the public with linear passage tolls. In 1998, Singapore discarded the manual system of road pricing in favor of Electronic Road Pricing, which permitted the charging of tolls per entry, based on vehicle size, route taken, and time of the day. This article traces the rationale for the various measures and discusses the successes and shortcomings for the various measures over a twenty-eight year period from 1975 to 2003. [ABSTRACT FROM AUTHOR]

This paper presents the development of models to estimate traffic generated by office and retail (shopping centre) developments in Singapore, based on surveys conducted at 27 representative sites. Of particular interest are the effects of the Singapore road pricing scheme and accessibility to public transport on traffic generated by these developments. Two different approaches were used to estimate vehicle trips generated by developments: weighted average rate and regression analysis. The study found that the mean trip rate for office sites located within the area charged under road pricing was lower than the rate for sites situated outside; however, the difference was not statistically significant. The mean trip rate for retail sites within the charged area during the weekday evening hour was significantly lower than the rate outside. For both office and retail developments there were strong linear relationships between traffic generated and floor area (either gross or leasable floor area). The inclusion of the variable `distance to the nearest Mass Rapid Transit (MRT) station' to represent accessibility to MRT services proved to be significant in explaining traffic generated for office developments but not for retail. Trip rates for office and retail developments were found to be considerably lower in Singapore than the UK and US rates. [ABSTRACT FROM AUTHOR]

• A heterogeneous network with signalized and non-signalized intersections is modelled. • A traffic light control problem based on proposed macroscopic model is formulated. • The problem is converted to a mixed integer linear problem for computational benefit. • Simulations are shown to provide guidance for the design of an urban traffic system. In this paper, one type of heterogeneous traffic network, which consists of signalized intersections and non-signalized ones, is analyzed and modelled with a macroscopic model and logic constraints, which involves the evolution of the number of vehicles on each link and the leaving flow dynamics at each intersection. We propose a novel model describing the dynamic behaviors of such a system and the proposed model is validated via road tests in Singapore traffic network and simulations in VISSIM. A piecewise linear model is adopted to describe the traffic flow dynamics at each signalized intersection, while a platooning-like first-in-first-out (FIFO) model is proposed to depict the dynamics at each non-signalized intersection. A traffic light control problem for a heterogeneous traffic network is formulated based on the proposed macroscopic model as a mixed integer programming problem. Simulations indicate that the proposed optimal traffic control scheme could outperform the fixed-time traffic light control strategy and conventional actuated traffic light control scheme. Besides, we demonstrate potentials in developing a systematic planning approach on deciding which traffic intersections require signal control to ensure good traffic control performance. [ABSTRACT FROM AUTHOR]

The article announces the award of grants by Mitsui Sumitomo Insurance Group (MSIG) to four projects from the National University of Singapore (NUS) on senior citizen welfare and traffic safety and four additional grants related to traffic safety in Thailand.

Focuses on a Web-based information system to stimulate and predict traffic conditions created by professor Der-Horng Lee and his colleges at the National University of Singapore in Singapore. Career background of Lee; Limitation of existing simulation software; Modules of the system's architecture.