The 公共工程 Department operates and maintains all traffic signals in the City. 交通信号 are valuable devices for the control of vehicle and pedestrian traffic. The public's understanding of the function of traffic signals can improve driving habits by slowing traffic and reducing traffic collisions. 了解交通信号工作原理的司机就越多, the less they will be frustrated when waiting for a signal to change.

交通信号灯故障?

Please have the intersection locations available when reporting the traffic signal malfunction. You can report the malfunction my visiting the office, email, or by phone. 为了获得最快的响应，请致电或访问海洋之神官方网站的办公室. 

西萨克拉门托市

西国会大道1110号

西萨克拉门托，加州95691

电话:(916)617-4850

邮箱地址:pwoffice@psychomotricite-la-seyne.com 

• 交通灯位置图

Are 交通信号 the Answer to Solving 交通 Problems?

优势

Signals offer maximum control at intersections--they relay messages to both what to do and what not to do. By alternately assigning right-of-way to various traffic movements, signals provide for the orderly movement of conflicting vehicles and pedestrians. They may interrupt the main street which carries extremely heavy flows to allow the minor street movements that could not otherwise move safely through an intersection. 当交通信号计时正确时, they increase the traffic handling capacity of an intersection and when installed under appropriate conditions a signal will improve efficiency and the safety for both vehicles and pedestrians. 特别是, signals can reduce the frequency of certain types of collisions, 尤其是直角(舷侧)碰撞.

缺点

交通信号灯并不是解决交通问题的“万灵药”. Even though warranted by the traffic and roadway conditions, 可怜的设计, 不好的位置, 操作不当, 或者糟糕的维护会使它们失效. While many people realize traffic signals can reduce right-angle collisions at an intersection, few realize that signals can also cause a significant increase in rear-end collisions. When there is no collision problem at an intersection and a signal is not needed for traffic control, there is no benefit to the installation of traffic signals. In fact, they can cause a reduction in the overall safety at the intersection. 不合理的信号也会导致过度的延迟, 信号不服从, 以及将交通引向居民区街道.

特殊信号函数

交通信号抢占

The transfer of normal traffic signal operation to a special operation is called preemption. There are three common types if preemption: Railroad Train, 紧急车辆, 或巴士/交通工具.

铁路抢占

Railroad preemptions happen when a train passes over detectors located on the tracks ahead of the railroad crossing. The purpose of the preemption is to clear tracks of traffic stopped on them by traffic signals.

紧急车辆优先权

In the 西萨克拉门托市, fire engines are the only emergency vehicle to use preemption. The purpose is to shorten response time by turning on a green light for the fire engine as soon as possible or holding an existing green light. 为了让消防车获得绿灯, 现有的绿灯, 包括行人间隔, 是缩短. The fire truck uses a strobe light to trigger a detector that is mounted on the signal.

巴士/运输车辆优先

The bus/transit vehicle preemption system is not used in the 西萨克拉门托市.

信号时间

信号时序目标

The goal of signal timing and coordination is to get the greatest number of vehicles through a particular corridor and to improve the flow of traffic along a major street or through a network of streets.

交通 signals assign the right-of-way to various traffic movements. The signals have preset time intervals for different times of the day, 包括早上, 中午, 以及晚高峰旅行时段. 定时计划通常由计时器选择. If a signal should get out of step, the system automatically corrects itself. The local controller for one intersection acts as the master controller for the system.

交通 actuated signals use detectors located in the pavement on the approaches to traffic signals to monitor and assign the right-of-way on the basis of changing traffic demand. These signals attempt to give most of the available green time to the heaviest traffic movements. The cost of an actuated signal is much greater than the cost of a pre-timed signal.

驱动和. 固定时间信号控制

交通 signals are programmed to produce the best flow of traffic for each individual intersection. Furthermore, there are different methods in which traffic signals are programmed to run. For example, signals can be timed to operate on an actuated or a fixed time signal control. 定时信号, 或者提前控制, is a consistent and regularly repeated sequence of signal indications that is given to traffic.

另一方面, semi-actuated or full-actuated timed signals occur when the duration of some or all of the intervals vary from cycle to cycle; or some phases may be omitted altogether during a cycle. The duration of some or all of the intervals and whether a phase is served or omitted is determined based on actuation from detection equipment.

协调与. 独立的交通信号运作

除了计时单独的交通信号, some signals are also timed as coordinated in order to achieve a total network of unified traffic signals. This is a predetermined timing relationship among adjacent signals. The goals of coordinating the signals are to minimize delay, 减少停, 并改善交通流量.

Free viewers are required for some of the attached documents.
他们可以通过点击下面的图标下载.

阅读器 Windows Media Player 词查看器 Excel查看器 PowerPoint查看器