In today's increasingly busy urban traffic, crosswalks, as an important facility for pedestrians to cross the street, are supposed to be a safe “green channel”. However, the latest report released by the World Health Organization is alarming: globally, about 274,000 people are involved in traffic accidents at crosswalks every year, with more than 60% of the accidents occurring at night, at dawn, or during periods of inclement weather. Behind these cold statistics are the pain of countless families, which also highlights the urgency of improving the safety of crosswalks. As a kind of innovative traffic safety facilities, solar road studs are bringing new hope for improving this situation with their unique technical advantages.
The energy conversion system of solar road studs is called a “miniature power station”. Its built-in solar panels, through the photoelectric effect of sunlight into electricity. Taking monocrystalline silicon solar panels as an example, its surface is covered with specially treated silicon wafers, which are capable of absorbing specific wavelengths of sunlight. When photons hit the silicon wafer, electrons are excited to produce electron-hole pairs, and under the action of semiconductor materials, the electrons and holes move in different directions, resulting in the formation of an electric current. In order to increase the energy conversion efficiency, modern solar studs use nanoscale coating technology, which can effectively reduce the reflection of light and increase the efficiency of photovoltaic conversion to 15% - 20%. In addition, the built-in high-efficiency lithium battery has excellent energy storage performance, even in continuous rainy days, but also to ensure that 3 - 5 days of continuous power supply.
The intelligent light-emitting system of the Solar stud consists of a light-sensing element, a micro-controller and an LED light set. When the ambient light intensity is lower than a specific threshold (generally set at 50 lux, equivalent to the light intensity at dusk), the light sensing element will immediately send a signal to the micro-controller. The microcontroller activates the LEDs according to a preset program. These LEDs are of a high brightness SMD design, with individual beads having a brightness of 3000 - 5000 mcd. In order to achieve the best warning effect, the studs support a variety of light modes: constant mode is suitable for low-light but good visibility environments; blinking mode attracts the driver's attention instantly by alternating light and dark in a high-frequency pattern (usually 60 - 120 times/minute); fading mode is a slow change of light and dark; and the light sensing element is a slow change of light and dark. Flashing Mode creates a soft and continuous warning effect by alternating light and dark at a high frequency (typically 60 - 120 times/minute).
Conventional crosswalk markings rely on reflective materials, which can be greatly affected at night or during inclement weather. When rain covers the reflective coating, or when the angle of vehicle light is poor, the visibility distance of the reflective sign will be shortened from 100 meters under normal conditions to less than 30 meters. With their active light-emitting properties, solar-powered road studs can maintain a clear visibility distance of more than 300 meters, even at night during heavy rainfall. In field tests in Bergen, Norway, in 2024, researchers compared the visibility of crosswalks with and without solar pins. The results showed that in foggy conditions, drivers on average could not see the signs until they were 25 meters away from the crosswalk in the section without solar pins; whereas in the section with solar pins, drivers were able to clearly identify them from 80 meters away, an increase in reaction time of 2.2 seconds, which was enough to avoid many potential traffic accidents.
The sensitivity of human visual system to dynamic objects is 3 - 5 times that of static objects, and solar road studs make use of this principle to realize active warning through dynamic light-emitting mode. When the vehicle is approaching, the flashing light of the road stud will break the visual balance of the surrounding environment, stimulate the retinal nerves of the driver, and make his brain react quickly. The American Transportation Research Association's experiments show that when drivers see flashing solar pins, their braking reaction speed than to see the static signs faster than 0.3 - 0.5 seconds.
Shenzhen's Binhai Avenue, after the installation of solar pavement studs, the average speed of vehicles in the crosswalk area from the original 50 km / h to 35 km / h, reducing the risk of collision by 60%. In addition, some of the solar road studs are also equipped with radar sensing device, when a pedestrian is detected near, will automatically enhance the brightness of the light or speed up the flashing frequency, to further enhance the warning effect.
The green features of solar road studs are in line with the global trend of sustainable development. Take a standard urban crosswalk (length 20 meters, installed 20 pins) as an example, if the use of traditional power-driven warning lights, the annual cost of electricity is about 800 - 1,000 yuan, but also need to lay the cable, the initial cost of the installation of up to 1.5 - 20,000 yuan. Solar road studs do not need external power supply, its initial installation cost is higher than the traditional road studs, although 20% - 30%, but almost no subsequent electricity expenses. In terms of maintenance, due to its simple structure, the average annual maintenance cost of each stud is only 5 - 10 dollars. In addition, the use of solar studs can also significantly reduce carbon emissions, each stud can reduce carbon dioxide emissions of about 50 kg per year, equivalent to the planting of 2 - 3 adult trees of carbon sequestration.
Solar stud's shell is made of high-strength engineering plastics or aerospace-grade aluminum alloy through a special injection molding or die-casting process. The housing not only provides excellent impact resistance, but also protects against UV rays, acid and alkali corrosion, and extreme temperatures. The solar road stud can work at an altitude of 4,500 meters and a minimum temperature of -45°C. The solar powered road stud is waterproof to IP68 standards. Its waterproof grade reaches IP68 standard, even if it is immersed in 1 meter deep water for a long time, it will not affect the internal circuit. At the same time, the bottom of the stud adopts a special anti-skid design and uses high-strength structural adhesive to bond with the road surface, which can withstand more than 20 tons of vehicle crushing, and remain stable after more than 100,000 times of vehicle crushing.
London, UK launched the “Safe Crossing Program” in 2020, installing solar studs at pedestrian crossings on 100 busy road sections. After a year of monitoring, the rate of pedestrian accidents on these roads dropped from an average of 2.3 to 1.5 accidents per year, a 35% reduction. The head of Transport for London said: “The solar pins not only enhance the safety of pedestrians, but also make drivers more consciously follow traffic rules.”
San Francisco, USA, is using solar studs on crosswalks around 200 schools in the city in 2022, in conjunction with the Safe Routes to School program. According to a survey, 85% of parents believe that the safety of their children going to and coming from school has been significantly improved, and the number of traffic accidents around schools has been reduced by 40%.
Hangzhou, China, has achieved remarkable results after installing solar road studs on roads around the West Lake scenic area. As a popular tourist attraction, the West Lake scenic spot has an average daily flow of more than 100,000 people, and the traffic situation is complicated. After the installation of solar road studs, the number of traffic accidents on pedestrian crossings at night dropped from a monthly average of 12 to 7, a reduction of 40%. To further evaluate the effect, the Hangzhou Traffic Management Department conducted a questionnaire survey of 1,000 drivers, which showed that 90% of the respondents said that the flashing lights of the solar road studs made it easier for them to pay attention to the crosswalks, and 85% were willing to voluntarily slow down for the road sections where the solar road studs had been installed.
Installation of solar studs needs to follow strict specifications.
First of all, in terms of installation location, 1 - 2 studs should be installed at each end of the crosswalk, and one every 2 - 3 meters in the middle to form a continuous warning strip.
Prior to installation, a pavement grinder should be used to grind the installation area to remove oil and loose particles and to ensure a close fit between the stud and the pavement.
During the installation, special structural adhesive is applied to the bottom of the stud, and then the stud is quickly pressed into the designated position to ensure that the solar panel is facing upwards and is perpendicular to the ground, with an error of no more than 5 degrees.
After the installation is completed, it should be left to stand for 24 hours until the glue is completely cured, and then carry out the power test. At the same time, be careful to avoid installing the stud in the shadow of trees or buildings to ensure that it can fully receive sunlight.
The daily maintenance of Solar stud mainly includes cleaning, inspection and replacement.
The surface of the solar panel should be wiped with a clean soft cloth and water every month to remove dust, bird droppings and other stains to maintain its good light transmission.
Quarterly inspection of the studs is required, including battery power, LED brightness, flashing frequency, etc. Professional inspection equipment can be used. Professional testing equipment, such as light intensity tester, battery capacity tester, etc. can be used for testing. If the battery power is found to be less than 50%, the need to replace the battery in a timely manner; if the LED lights appear to be insufficient brightness or does not light up the situation, you should check whether the circuit connection is loose, and if necessary, replace the LED lamp beads. For loose pins, glue should be reapplied in time to ensure its stability.
In addition, the waterproof performance of the stud should be tested every year to prevent damage to the internal circuit due to sealing failure.
The first is the improvement of photoelectric conversion efficiency, scientists are researching and developing a new type of chalcogenide solar energy materials, the theoretical conversion efficiency of this material can reach more than 35%, and the cost is lower, more flexible, and is expected to be applied to the solar energy dowel.
Second is the upgrading of intelligent control technology, through the integration of 5G communication module and artificial intelligence algorithms, solar road studs will be able to interact in real time with traffic signals, vehicle automatic driving system. For example, when the traffic signal turns green, the stud can automatically adjust to a low-brightness mode; when an elderly person or a child is detected crossing the street slowly, the stud will extend the blinking time.
Finally, the optimization of the energy management system, the use of super capacitors and other new energy storage devices, can achieve rapid charging and discharging, and further enhance the stability of the stud in extreme weather.
With the continuous progress of technology, the application scenario of solar road studs will no longer be limited to pedestrian crossings. On the highway, it can be used at the entrance and exit of toll booths, tunnel entrances, long downhill sections and other dangerous areas, through dynamic lighting to remind drivers to pay attention to road conditions. In scenic spots and parks, solar road studs can be used as a dual tool of landscape lighting and safety warning, which can create a unique night landscape and protect the safety of visitors. In addition, in rural roads, campus runways, community trails and other scenes, solar road studs also have a broad application prospects. In the future, solar road studs will become an important part of building intelligent transportation and safe communities.
Solar road studs provide strong support for enhancing pedestrian safety at crosswalks with their advanced technical principles, excellent safety performance and broad development prospects. From the all-weather high visibility warning effect, to the economic advantages of energy saving and environmental protection; from the durable quality guarantee, to the development potential of intelligent innovation, solar road studs are undoubtedly an important innovation of modern transportation facilities.
In the face of serious pedestrian safety issues, we look forward to more city managers, transportation departments and enterprises to pay attention to and promote the application of solar road studs. I believe that in the near future, solar road studs will be all over the city streets and alleys, become the guardian of pedestrian safety “intelligent guardian”, and jointly build a safer, more efficient, green transportation environment.
