On each weekday, some 750,000 vehicles use the Ayalon Highway, which serves as a fast metropolitan freeway for the millions of inhabitants of the Tel Aviv metropolitan region ( "Gush Dan").
The Ayalon Highway is one of the top level roads in Israel. Built to the highest standards, it enjoys a high standard of supervision and maintenance. It was designed as a freeway, with 3 lanes in each direction, from the Herzlia interchange in the north, to the Holot and Kibbutz Galuyot interchanges in the south.
In January 2000, a traffic control system was inaugurated in the central part on the Ayalon Highway, the first of its kind in Israel. The system was designed and built with the aid of leading and experienced companies in the field both from Israel and abroad. Similar systems have been installed on freeways in the United States, Europe and Japan.
Today, there is full deployment of cameras along the Ayalon Highway, and soon, an advanced traffic control system will be installed also in the southern part of the highway to complete the system.
?How does it work
The Ayalon Highway traffic control system operates 24 hours a day, 365 days a year. The system incorporates means for data collection including traffic detectors and cameras, a manned control center, data dissemination system, and an advanced communications system. The system includes an advanced computerized system operated by an experienced team of operators who decide the appropriate course of action for every situation.
The system components are described below.
The control center is at the very heart of the system, including all that is required for advanced traffic management. Every operator station is equipped with a terminal connected to the
central computer and with camera control, telephones and radio communication equipment.
A large video wall is dedicated to displaying video images received from the cameras as well as an electronic map displaying data received in real time from the data collection system.
When an alert is received caused by an irregular event, the control center acts as an operations room, linked directly to the emergency services (Police, MDA, fire fighting services), as well as to other control centers. The operator uses the cameras to verify the nature of the incident, and if necessary, utilizes the traffic control signs situated along the road to direct traffic and alerts the appropriate entities.
The communications network links the data collection system on the Highway with the traffic control center. This Ethernet based communication system uses a fiber optic network which runs along the road.
Data Collection System
Sixty detector stations collect data from 500 loop detectors installed at intervals of 500m. These detectors provide updated information on traffic characteristics: traffic volume, travel speed, vehicle types, and density. The data is reported every 5 minutes and processed by the central computer which identifies changes in traffic flows and issues the relevant alerts.
Traffic Control Cameras
Nearly 50 closed circuit television (CCTV) cameras are situated at key locations, providing full coverage of the activity along the Highway. The operator can control the cameras and use them to track the traffic status and manage incidents until the road is cleared. The cameras are intended exclusively for traffic control, and are not used for law enforcement purposes.
Variable Text Signs
Seven gantry-mounted electronic signs (six signs along the road and another one on Road No. 5 before the turn-off to the Ayalon Highway) enable the display of text messages sent from the control center. The information includes the state of traffic ahead and allows drivers to select an alternative route.
Lane Control Signs
Electronic traffic signs are mounted on thirty two gantries situated along the Highway and controlled by the traffic control center. Each traffic sign addresses the traffic in the lane under it. The signs enable the display of the speed limit, warnings of traffic congestion, closing the lane or diverting traffic between lanes. The traffic signs have been certified by the Ministry of Transportation, and are binding, just as any regular traffic sign
An exclusive expert system at the traffic control center analyzes the information received from the traffic detectors, distinguishes between traffic situations, tracks their development, and recommends a strategy of action to the operator. This strategy, including details of the messages and traffic signs to be displayed on the variable message signs and lane control signs. It is up to the operator to approve, modify or reject the strategy.
Information Dissemination System
In addition to displaying direct traffic information to highway users, up-to-date traffic information is also disseminated to radio stations and other media channels. Information about anticipated disruptions caused by road works is provided to the media in advance. The traffic control center is updated by, and exchanges information with, the control centers of the Israeli Police, the National Highway Company and the Tel Aviv Urban Traffic Control Center.
The system objectives are optimal utilization of the existing infrastructure, reduced traffic congestion, and
improved safety levels. The Ayalon Highway is the busiest route in the country. Large traffic volumes on the one hand and limited road capacity on the other create excessive congestion. The Ayalon Highway can function at 90% utilization of its capacity enabling a travel speed of 50-60 km/h, but any increase in traffic volume beyond that, is liable to cause a traffic jam.
Traffic jams are a national problem. Time lost by the public in traffic jams causes enormous losses to the economy, in the billions of Shekels. Traffic jams result in the waste of costly gasoline, and increase air pollution and risk of accidents.
The traffic control system enables a quick response to traffic disruptions caused by accidents, road works, a stranded vehicle or cargo that has accidently spilled onto the road. In cases of heavy congestion, any disruption is likely to cause a traffic jam, increasing the likelihood of accidents. Quick handling and clearing of the disruption greatly reduces the risk of accidents or of secondary accidents following an accident.
Control Center Operatio
The main function of the system is the quick identification, handling and clearing of road disturbances (accidents, stranded vehicles, etc.). The traffic control center is linked to the Israel Police, MDA, fire fighting services, Tel Aviv Municipality and the Israel Highway Company. A rapid response and quick clearing of the disturbance reduces traffic disruptions and risk of accidents. The system also reduces the arrival time of the emergency services, and helps save lives.
Provision of Traffic Information
Reliable, up-to-date information on traffic is disseminated to drivers via electronic signs and over the radio, enabling drivers to choose the optimal route and minimize journey time.
Overhead electronic traffic signs inform drivers about lane closures due to road works or other incidents on the Highway, enabling convenient and safe lane changes.
The electronic traffic signs provide drivers with early warning about traffic congestion and obstacles ahead, enabling gradual reduction in speed and reducing the risk of an accident.
The system calculates the optimal speed on the Highway ("traffic smoothing") and displays it on the electronic traffic signs. This guidance contributes to optimal utilization of the Highway and prevents sudden changes in speed which may result in accidents.
Traffic Light Coordination
Cooperation with the Tel Aviv Municipality Urban Traffic control Center helps reduce queuing on highway exits, which might otherwise block lanes on the Highway.
The traffic control center is linked to the control centers of the Police, the Israel Highway Company and the Tel Aviv Municipality, in order to exchange information and coordinate control operations.