Search Results (5)

There are many visually impaired people globally, and it is important to support their ability to walk independently. Acoustic signals and escort zones have been installed on pedestrian crossings for the visually impaired people to walk safely; however, pedestrian accidents, including those involving the visually impaired, continue to occur. Therefore, to realize safe walking for the visually impaired on pedestrian crossings, we present an automatic sensing method for pedestrian crossings using images from cameras attached to them. Because the white rectangular stripes that mark pedestrian crossings are aligned, we focused on the edges of these rectangular stripes and proposed a novel pedestrian crossing sensing method based on the dispersion of the slope of a straight line in Hough space. Our proposed method possesses unique characteristics that allow it to effectively handle challenging scenarios that traditional methods struggle with. It excels at detecting crosswalks even in low-light conditions during nighttime when illumination levels may vary. Moreover, it can detect crosswalks even when certain areas are partially obscured by objects or obstructions. By minimizing computational costs, our method achieves high real-time performance, ensuring efficient and timely crosswalk detection in real-world environments. Specifically, our proposed method demonstrates an impressive accuracy rate of 98.47%. Additionally, the algorithm can be executed at almost real-time speeds (approximately 10.5 fps) using a Jetson Nano small-type computer, showcasing its suitability as a wearable device. Full article

The concurrent worldwide energy crisis has become a strong incentive for researchers, governments, and industry professionals to focus on sustainable energy solutions. Consequently, pavement photovoltaic energy harvesting technologies, as one of the most common sustainable energy solutions, have recently seen a significant improvement, especially in the new innovative designs of pavement solar panels. In this study, an innovative design for a prototype energy harvesting system was proposed based on thin-film photovoltaic solar panels. In addition, the feasibility of utilizing the generated power of the proposed system to illuminate a pedestrian crosswalk to enhance the safety of an at-grade intersection was also analyzed. The designed prototype consists of a thin-film solar panel, a transparent cover to protect the solar panel, and a wooden frame to support the panel and distribute the load. Different materials for the transparent covering plates were investigated, including polycarbonate with varying thicknesses, textured GlassGrit, and textured float glass with corundum skid-resistant coating on the surface. Finite element analysis was also conducted to analyze the behavior of solar panel-incorporated layered asphalt pavement subjected to dynamic wheel loading. The results showed that the suggested model could sustain the structural loads of a moving wheel without failure. Experimental results of the study showed that considering the seven hours of operation on a typical sunny day, the proposed system could generate approximately 699 Watt-hour of power during 7 h of operation (9 a.m.–4 p.m.) from the 304.8 mm (12 inches) × 304.8 mm (12 inches) pavement solar panel. Full article

In the last decade, pedestrian fatalities at night, especially at midblock locations, have been increasing at an alarming rate. Lighting is an effective countermeasure in reducing nighttime crashes. However, few studies have evaluated the effects of crosswalk lighting on pedestrian visibility at midblock locations. There is an existing need to develop lighting designs that increase pedestrian visibility. Further, the safety effects of lighting have never been directly compared to other pedestrian-crossing treatments (such as flashing signs, rectangular rapid flashing beacons (RRFBs), etc.). Thus, in order to make effective recommendations for increasing nighttime pedestrian visibility, it is important to compare the visibility benefits of crosswalk lighting designs with and without pedestrian-crossing treatments. This study evaluated the visual performance of five midblock crosswalk lighting designs along with two pedestrian safety countermeasures at three light levels on a realistic midblock crosswalk. Visual performance was measured by calculating the distance at which the participants could detect a child-sized mannequin under the evaluated conditions. The results showed that midblock crosswalks should be illuminated to an average vertical illuminance of 10 lux to ensure optimal pedestrian visibility. Lighting designs that render the pedestrian in positive contrast (area in front of the crosswalk is illuminated) are recommended to increase pedestrian visibility. It is also recommended that pedestrian-crossing treatments, such as RRFBs and flashing signs, should be used with lighting to increase nighttime visibility. Full article

The main goal of roadway lighting design is ensuring compliance with mandatory lighting standards and thus increasing safety for all road users. On the other hand, a design process being only a part of a road investment has to be completed in possibly a short time, due to business needs. The commonly used method for reconciling both requirements is using predefined lighting projects (templates) which are matched with similar, real-life lighting situations. This approach works well for a typical roadway lighting design but not necessarily for crosswalk illumination due to different specifics of underlying calculations (they focus on the contrast of a pedestrian against its background rather than roadway illumination). As one deals with pedestrian safety here, we decided to perform extensive tests to find out whether a standard compliant lighting project prepared for a given crosswalk can be safely applied (in terms of preserving standard compliance) to another similar crosswalk. To accomplish that, we investigated nearly 900 million situations obtained as modifications of the reference template. Results proved that even a 5% change of layout sizes (crosswalk width, lamp spacing, pole height etc.) makes 40% of obtained projects violate illumination requirements. The conclusion of this result is that the template-based design approach broadly used for roadway lighting cannot be applied for pedestrian crossings as it may cause serious safety issues. Full article

The research presented in this paper is focused on the definition of a new methodology for evaluating how illuminated crosswalks influence drivers’ behavior when approaching the zebra in nighttime conditions. The proposed methodology is based on in situ speed measurements, and cars’ speed was detected in an urban road segment of the city of Rome with a Telelaser instrument. Vehicles speed profiles are measured in the same road segment both in LED-illuminated conditions and in non-illuminated conditions. Results have shown a promising impact of the LED lighting system on pedestrian safety. In fact, cars’ mean speed decreases by 19.3% at the crosswalk section in illuminated conditions. Moreover, a positive effect on safety, in terms of mean speed reduction (−16.4%), was found even in the absence of pedestrians. Full article