In recent years, with the country's strong support for rural transportation, the development of rural roads has progressed by leaps and bounds, and the fundamental realization of "the road must be maintained, and the maintenance must be in place." Over the past decade, the total length of rural roads in China increased from 3.564 million km in 2012 to 4.466 million km in 2022, a net increase of more than 900,000 km. Rural roads bring convenience to people's production and life and guarantee rural economic development. Due to the inherent traffic characteristics of rural roads: few road markings, poor sight distance; serious mixing of pedestrians and non-motorized vehicles at intersections; and low awareness of traffic safety among rural people, traffic accidents at intersections are about 1.3 times higher than those on ordinary roads. Of these accidents, speeding accounted for 25.13 % of the total casualties. Although speed limit signs have been set up at some intersections, the lack of appropriate monitoring facilities has not been effective. Currently, some rural road intersections are equipped with speed bumps, which are of different forms, heights, widths, and spacing, and have poor visibility at night, resulting in accidents involving electric vehicles and cars that are too late to slow down. Based on a comparative analysis of several commonly used speed bumps' advantages, disadvantages, and costs, we suggest selecting speed bumps to provide a reference for improving rural roads.

                                      

Four common speed bumps

According to the survey, the speed bumps on the market at present mainly include rubber speed bumps, cast steel speed bumps, concrete speed bumps, and solar speed bumps.

1. Rubber speed bump

The rubber speed bump is made of rubber material with a sloped shape, and the color is often yellow and black. It is fixed to the road intersection with expansion screws. It is a safety device for vehicle deceleration. The scientific name is rubber deceleration ridge, designed according to the principle of the angle between the tire and the unique rubber on the ground when the vehicle is running and is made of unique rubber. It is a new type of traffic safety device set at the entrances of highway crossings, industrial and mining enterprises, schools, residential areas, and other places to slow the speed of the motor and non-motor vehicles.

The rubber speed bump has shock absorption characteristics, excellent compression resistance, long service life, less wear on the vehicle, less noise, yellow and black, transparent color, no need to paint every year, and is beautiful and generous. After using this rubber speed bump, accidents at major traffic crossings have been significantly reduced. It is a new particular facility for traffic safety.

2. Cast steel speed bump

Compared with rubber speed bumps, the main difference between the two is the different materials. This product is made of high-strength special steel, which is durable and bears about 200 tons. The standard yellow and black production process is adopted, with bright colors, transparent colors, and apparent signs. It has high visibility both during the day and at night, attracting drivers to pay attention to slowing down. The "internal expansion anchoring technology" is used for firm installation, which is stable and reliable. The disadvantage is that the cost is higher than a rubber speed bump.

3. Concrete speed bump

The concrete speed bump is made of cement and is rectangular and vertical on the road. The speed bump has the advantages of effectively reducing the speed and low cost. Disadvantages: when the vehicle passes, it is easy to generate noise, poor driving comfort, and there are specific safety hazards. The plate is easy to break off after long-term use, and the construction process will cause unavoidable damage to the pavement during installation, increasing the pavement's maintenance cost.

4. Solar speed bump

The solar speed bump combines the solar spike with the circular speed bump. The circular speed bump has a slot about the size of the solar spike at the top, and the solar spike is fixed at the top of the circular speed bump. The feature of solar energy spike's active lighting at night makes the warning effect of the deceleration belt better, but the disadvantage is the high cost.

Comparison & analysis

The advantages and disadvantages of various speed bumps are shown in Table 1.

                                                         

                                                                                                                  Tabe 1 
We selected the typical speed bumps on the market (1000X350X50mm), referred to the product's unit price on the e-commerce platform and on-site inquiry, and calculated the price as shown in Table 2.

                                                                                                                         

                                                                                                                   Table 2
Based on the above advantages and disadvantages and cost analysis, combined with the limited funds for rural road maintenance, rubber speed bumps are still the best choice for rural roads, which is of great significance in reducing speed, eliminating potential safety hazards, and reducing the accident rate.