Objective

To design and build prototypes of low-cost sensor and wireless communication systems for vehicle detection, and to test the prototype systems for applications in freeways traffic measurement, urban intersection control, and parking management. The proposed systems are networks of 2-inch nodes comprising acoustic or magnetic sensors, a processor, a radio, and a battery. Each node would fit into a form factor of a Bott's dot or SmartStud. The first-year effort will lead to two system designs-the basic system and the advanced system. The basic system will

1. measure per lane 30-second vehicle counts and occupancy of freeway traffic, and
2. detect the arrival, departure, and presence of vehicles at urban intersections and for parking applications. Field tests (on I-80 and San Pablo Avenue) will compare the basic system prototype measurements side-by-side with loop detector measurements.

The advanced system, based on distributed processing by a sensor node array, will have more advanced capabilities, including estimating vehicle speed and vehicle 'signature' and detection of vehicle presence over a wide area. Limited testing of this prototype will be conducted at the Richmond Field Station.

Methodology

The first step is to design a wireless sensor system and prototype the design so that it can be tested in the field. In terms of the sensor nodes this requires:

1. circuit design and fabrication of a circuit board that can fit in the required form factor;
2. design and implementation of the signal processing algorithms for vehicle detection;
3. design and implementation of a communication protocol with the required power efficiency and delay guarantees.

The second step is to test the prototype designs and determine if they meet the functional requirements for

1. urban intersections;
2. freeway locations;
3. parking lots.

The testing will initially be carried out in a controlled environment at Richmond Field Station.