Towable crash-attenuating vehicle

1. A towable crash-attenuating vehicle comprising:

a frame having a right side, a left side, a front end and a rear end;

at least two axles coupled to the frame, each of said axles having wheels attached thereto;

a ballast coupled to the frame;

deflection shields coupled to the right and left sides of the frame, wherein said deflection shields cover the frame and a majority of the wheels on each side of the vehicle;

a tow connection coupled to the front of the frame;

an impact attenuator coupled to the rear of the frame;

wherein the vehicle is provided with a brake system, and wherein said the vehicle is provided with a mechanism for locking and unlocking the brake system.

2. The towable crash-attenuating vehicle of claim 1 , wherein the brake system is an air brake system.

3. The towable crash-attenuating vehicle of claim 2 , wherein the air brake system locks the brakes when the brake is applied or when pressure is removed from the system and unlocks the brakes when neutral air pressure is supplied to the system.

4. The towable crash-attenuating vehicle of claim 2 , wherein the mechanism for locking and unlocking the brake system is an air compressor.

5. The towable crash-attenuating vehicle of claim 1 , wherein the brake system is a hydraulic brake system.

6. The towable crash-attenuating vehicle of claim 5 , wherein the hydraulic brake system uses hydraulic pressure from a host vehicle to lock the brakes, and has valves to retain the hydraulic pressure in the hydraulic brake system.

7. The towable crash-attenuating vehicle of claim 6 , wherein the valves are manually-actuated or electrically-actuated valves.

8. The towable crash-attenuating vehicle of claim 6 , wherein the brakes system is unlocked by opening the valves to release the hydraulic pressure in the hydraulic brake system.

9. The towable crash-attenuating vehicle of claim 5 , wherein the mechanism for locking and unlocking the brake system is a hydraulic pump.

10. The towable crash-attenuating vehicle of claim 9 , wherein the brake system is locked by providing pressure from the hydraulic pump.

11. The towable crash-attenuating vehicle of claim 9 , wherein the brake system is unlocked by deactivating the hydraulic pump.

12. The towable crash-attenuating vehicle of claim 1 further comprising on-board warning lights.

13. The towable crash-attenuating vehicle of claim 1 further comprising on-board solar panels to power the on-board mechanism for locking and unlocking the brake system.

14. The towable crash-attenuating vehicle of claim 1 further comprising an on-board generator to power the on-board mechanism for locking and unlocking the brake system.

15. The towable crash-attenuating vehicle of claim 1 further comprising an on-board battery to power the on-board mechanism for locking and unlocking the brake system.

16. The towable crash-attenuating vehicle of claim 1 , wherein the deflection shields are comprised of steel plates or hardened aluminum plates.

17. The towable crash-attenuating vehicle of claim 1 , wherein the ballast is comprised of a material selected from the group comprising concrete, crushed rock, sand, dirt, water, metallic and/or composite ballast material or other suitable materials of adequate weight.

18. The towable crash-attenuating vehicle of claim 17 , wherein the ballast is defined by at sheet metal box for containing the concrete.

19. The towable crash-attenuating vehicle of claim 18 , wherein the sheet metal box has lateral and longitudinal stringers for dividing the concrete in the ballast into sections.

20. The towable crash-attenuating vehicle of claim 18 , wherein the sheet metal box is further provided with a top cover and drain holes.