Aim:
To prevent accidents by reducing stopping distance.

Motive:
A recent study has concluded that the most of the accidents can be prevented by more effective braking i.e. reduced stopping distance*.

Principal:
Increases in contact surface of the tires, increase the road traction**, thereby decreasing the stopping distance.

Components:
 Sensor to measure the brake pedal speed, speed senor to measure the vehicle speed, microcontroller board to control the entire system, gas cylinder and air compressor to inflate the tires, vacuum cylinder and vacuum pump to deflate the tires with maximum possible speed, electronically controlled valve switch to open channel to inflate or deflate, rotary valve that constantly connect the wheel to the valve controls during rotary motion of the wheel. An auto pressure switch will be installed in order to control the inflation pressure. All the components are shown in the Figure (1) in as a layout.

Working: when the sensor reading from the brake pedal is above the threshold value then the system checks the vehicle speed if its above 50km/hr then the system is triggered, this is made on the assumption that the brake is completely effective under this speed. Once the system is triggered, the valve switches open the channel to the vacuum chamber so that the air from the tires can deflate faster increasing the contact surface simultaneously to reduce the stopping distance Figure (2a). Once the vehicle reaches zero velocity, the control switch changes the channel to the air compressor which inflates the tire to the prescribed pressure with the help of the auto pressure switch(2b). The vacuum pump will be used to create the vacuum again in the vacuum chamber. The both vacuum pump and air compressor are built with automatic on and off based on the pressure inside the cylinders

Results and conclusion:
The Figure (3) represents the contact surface before and after the deflation it has been shown that there has been increases in the contact surface of about 2r. Where r is the corner surface of the tires. The decrease in stopping distance is directly proportional to the decrease in the tire pressure. This system is next in line of existing technology such as ABS, ESP and EBS (Emergency Brake Assist System).

Note:
The sudden decrease in pressure may result in loss of steering control. But, with the power steering and ABS which is a common feature in modern cars, this can be easily overcome. The space required for this system can be accompanied in the cars boot space.
Using this system tire pressure can be altered to increases traction during rainy and snowy days.
*- Distance between the instance where brake applied and the vehicle stops
**- friction between road and the tire.

The working prototype is under construction of its final stage.