【正文】 ad. The first system proposed for adaptive signaling was based on digital image processing techniques. This system works based on the captured visual input from the roads and processing them to find which road has dense traffic. This system fails during environmental interaction like rain or fog. Also this system in testing does not prove efficient. The advanced system in testing at Pittsburgh [2] involves signals municating with each other and also with the vehicles. The proposed system does not require a work between signals and vehicles and is a standalone system at each intersection. III. THE PROPOSED SYSTEM This paper presents the concept of intelligent traffic routing using wireless sensor works. The primary elements of this system are the sensor nodes or motes consisting of sensors and a transmitter. The sensors interact with the physical environment while the transmitter pages the sensor’ s data to the central controller. This system involves the 4 x 2 array of sensor nodes in each road. This signifies 4 levels of traffic and 2 lanes in each road. The sensors are ultrasonic or IR based optical sensors which transmits status based on presence of vehicle near it. The sensor nodes transmit at specified time intervals via ZigBee protocol to the central controller placed at every intersection. The controller receives the signal and putes which road and which lane has to be given green signal based on the density of traffic. The controller makes use of the discussed algorithm to perform the intelligent traffic routing. IV. COMPONENTS INVOLVED IN THE SYSTEM The proposed system involves wireless sensor works which are prised of three basic ponents: the sensor nodes or motes, power source and a central controller. The motes in turn are prised of Sensors and transceiver module. The sensors sense the vehicles at intersections and transceiver transmit the sensor’ s data to the central controller through a wireless medium. The Power source provides the power needed for the sensor nodes and is mostly regenerative. The central controller performs all the putations for the sensor works. The controller receives the input from all sensors and processes simultaneously to make the required decisions. Sensors are hardware devices that produce a measurable response to a change in a physical condition like temperature or pressure. Sensors measure physical data of the parameter to be monitored. The continual analog signal produced by the sensors is digitized by an analogtodigital converter and sent to controllers for further processing. A sensor node should be small in size, consume extremely low energy, operate in high volumetric densities, be autonomous and operate unattended, and be adaptive to the environment. As wireless sensor nodes are typically very small electronic devices, they can only be equipped with a limited power source of less than amperehour and volts. Sensors are classified into three categories: passive Omnidirectional sensors。 and GHz. The functionality of bothtransmitter and receiver are bined into a single deviceknown as a transceiver [3]. To bring about uniqueness in transmitting and receiving toany particular device various protocols/algorithms are devised. The Motes are often are often provided with powerful transmitters and receivers collectively known as transceivers for better long range operation and also toachieve better quality of transmission/reception in any environmental conditions. F. Power Source The sensor node consumes power for sensing, municating and data processing. More energy is required for data munication than any other process. Power is stored either in batteries or capacitors. Batteries, both rechargeable and nonrechargeable, are the main source of power supply for sensor nodes. Current sensors are able to renew their energy from solar sources, temperature differences, or vibration. Two power saving policies used are Dynamic Power Management (DPM) and Dynamic Voltage Scaling (DVS). DPM conserves power by shutting down parts of the sensor node which are not currently used or active. A DVS scheme varies the power levels within the sensor node depending on the nondeterministic workload. By varying the voltage along with the frequency, it is possible to obtain quadratic reduction in power consumption. G. Tmote Sky Tmote Sky is an ultra low power wireless module for use in sensor works, monitoring applications, and rapid application prototyping. Tmote Sky leverages industry standards like USB and to interoperate seamlessly with other devices. By using industry standards, integrating humidity, temperature, and light sensors, and providing flexible interconnection with peripherals, Tmote Sky enables a wide range of mesh work applications [4]. The TMote is one of the most monly used motes in wireless sensor technology. Any type of sensor can be used in bination with this type of mote. Tmote Sky features the Chipcon CC2420 radio for wireless munications. The CC2420 is an IEEE pliant radio providing the PHY and some MAC functions [5]. With sensitivity exceeding the IEEE specification and low power operation, the CC2420 provides reliable wireless munication. The CC2420 is highly configurable for many applications with the default radio settings providing IEEE pliance. ZigBee specifications can be implemented using the builtin wireless transmitter in the Tmote Sky. Fig. 3 Tmote Sky H. Tmote Key Features ? 250kbps IEEE Chipcon Wireless Transceiver ? Interoperability with othe