Increasing the speed of vehicles at intersections is beneficial to slow congestion and ensure smooth traffic, but in order to ensure traffic safety, the traffic police require that the distance between two adjacent vehicles on the same lane be kept at least 4 meters, assuming that the average length of each vehicle is 5 meters. The average speed of the vehicle is 10.8 km/h, so how many vehicles can pass through the intersection on one side and one lane during the 90-second green light time, without counting the turning vehicles.
提高车辆在十字路口的通行速度有利于缓堵保畅，但为确保交通安全，交警要求同一行驶道上相邻两车之间的车距最少保持4米，假设每辆车平均长5米．平均车速为10.8千米/小时，那么在90秒的绿灯时间内，在不记拐弯车的情况下，该十字口单侧单道最多可以通过多少辆车．
<gadget id="calculator">1_000 / 3_600</gadget>
<output>5/18 = around 0.277778</output>

<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">90 / 9</gadget>
<output>10</output>

<gadget id="calculator">10.8 * (5/18) * 10</gadget>
<output>30</output>

<gadget id="calculator">30 + 1</gadget>
<output>31</output>

<result>31</result>