Visible light communication for intelligent transportation systems:A review of the latest technologies

In seeking to improve traffic congestion and safety on roads and highways,there has been an increased interest in intelligent transportation systems(ITS).The emerging visible light communication(VLC)technology is a new candidate to enable wireless access in ITS.The purpose of this study is to present a comprehensive review of the current studies related to VLC.Since VLC facilitates illumination and data communication simultaneously,it reduces energy consumption significantly.Additionally,VLC is immune to electromagnetic interference,provides high data security,and utilizes unregulated visible light spectrum,showing promise as a potentially cheaper alternative to existing radio frequency(RF)based technology.Moreover,recent advances in semiconductor materials and solid-state technologies have enabled the development of efficient light-emitting diodes(LEDs)and laser diodes(LDs)which are used as transmitters in a VLC system.Although 10 s of Gbits/s data rate has been demonstrated in indoor VLC links,successful implementation of it in outdoor environments requires further research to overcome the challenges presented by environmental factors,unwanted lights,non-line of sight communication,directional radiation pattern,frequent fragmentation,and so on.Besides,in recent years,semiconductor LDs have been garnering more attention since they can transmit more data over longer distances due to their high quantum efficiency and modulation bandwidth compared to LEDs.As a result,urban planners,policy-makers,transportation engineers,and vehicle manufacturers are considering LD-based VLC to facilitate vehicle-to-vehicle and vehicle-to-infrastructure communication.Thus,this paper reviews and compares the most recent developments in VLC technologies,identifies their benefits and potential use in ITS applications,discusses the probable barriers for their implementation in our existing transportation infrastructure,and suggests future research directions and recommendations to overcome these challenges.

Parking detection method using quadtree decomposition analysis

Searching for available parking spaces can be a painful experience for drivers due to driving around until finding a vacant space.This study proposes a new method to automatically detect available parking spaces.The proposed system identifies empty parking spaces using grayscale images obtained from any type of video camera.The method was found to successfully identify parking availability under different conditions and scenarios.The method was tested using real-life data and achieved a detection rate of 99.7%.This method can be applied in real-time to monitor parking availability and guide drivers to empty spaces.The method has several advantages,including simple algorithms,the use of low-quality black and white images,and simple configuration.Therefore,the system can provide enormous cost savings for locations with existing black and white surveillance cameras instead of replacing existing cameras with new high-quality cameras.

Effect of vehicle safety recalls on the perception towards other vehicles from the same country of origin

A vehicle safety recall significantly impacts the demand for these specific manufacturer vehicles.The effect of this recall on the other manufacturers from the same country of origin(COO) that are not involved in the recall is poorly understood.The purpose of this study is to examine the impact of a vehicle safety recall on other vehicle brands originating from the same COO.The study uses a case study related to Toyota recalls and the impact of the crises on the attitudes toward three other Japanese brands-namely,Honda,Nissan,and Mazda.A questionnaire was conducted with 375 participants who are familiar with the recalls.The findings from the questionnaire indicated that product-harm crises have an indirect negative effect on brands from the same COO.Thus,brands from the transgressor’s COO should not make the transgressor’s betrayal salient,which might hurt their brands.For example,if Honda makes the betrayal of Toyota salient through comparative advertising,Honda’s efforts might hurt the company directly through consumers’ image of Japanese products.Future research should examine the extent to which comparative advertising impacts non-transgressing brands that originate from the same country as the transgressing brand.The current results suggest that the non-transgressing companies might even assist the transgressing company to recover from such crises if consumers perceive a strong association between the non-transgressing brands and transgressing brands.

Evaluation of red-light camera enforcement using traffic violations

The State of O.atar started to use red-light cameras in 2007 at key signalized intersections and the rate of installation has subsequently increased. In 2017, 19.2% of signalized intersections are equipped with red-light cameras. In many cases, the cameras are not installed on all approaches to the intersections. The purpose of this study is to compare the red-light running violations on approaches with and without red-light running enforcement cameras at the same intersections. Actual field observations were used in this study. Different vari- ables were investigated, including the day of the week, time of day, traffic volume, the possibility of glare on an approach, and the lengths of the yellow and all-red times. A regression tree model was used to explain the characteristics associated with the violations. The results showed that the number of violations on low-volume approaches was five times higher than on high-volume approaches. The results also showed that the presence of the cameras significantly lowered red-light running violations. High-volume approaches without cameras had an approximately eight times higher rate of violations than high-vol- ume approaches with cameras. The analysis also showed that bringing the all-red interval closer to the values recommended by the Institute of Transportation Engineers formula may bring down the rates of violations for low-volume approaches. As with any observational data mining method, the study could benefit from a larger sample size. The method used in the study was effective and is easily transferable to other locations. The results of this study can be used in developing new strategies to improve safety at signalized intersections.