Highway safety has always been a great concern. Many thousands of people lose their lives every year in highway accidents. This new invention may be able to save some of those lives.
Driving on highways can become dull and boring. It is easy to get distracted on a long drive, and become less attentive to the many potential dangers. An Arizona State Police Officer once told me that there are a lot of high-speed single-vehicle crashes on the Interstate highways there. He explained that people had often already driven many hours before getting to the relatively uninteresting highway stretches in his state. He mentioned that some of the accident vehicles were traveling over 100 mph when they veered off the road, often because the driver had fallen asleep.
Some highway departments have installed bright reflective bumps on the lane dividers and at the edge of the highway. The flashing reflected lights (at night) and thumping sounds are advantageous and have certainly awakened many drivers. There is a wonderful improvement of this approach! Instead of being alerted by monotonous thumps, what about if you heard a VOICE warning you about the impending danger? That is the idea of this invention!
You may have approached a highway toll booth and run over some groups of ridges or grooves and heard a deep growling sound in your car. You probably have also driven over a steel bridge that had a deck made of gratings (mostly so rain could fall through.) When you drove over those gratings, you heard a singing sound from your tires. Very few people seem to notice but the speed you drove over the gratings had an effect on the sound: when you drive faster, the pitch of the singing is higher.
I propose to install a sequence of irregular bumps or grooves (either will work) along a highway. For example, along the edge of the pavement (before the shoulder) a six-inch wide strip of these bumps or grooves would be installed. As the tires of the vehicle roll over them, a vibration is induced in the body of the tire. This vibration is conducted through the vehicle's suspension to the body of the vehicle and finally into the passenger compartment. This is the actual reason that you hear that growl or singing of your tires as you pass over the warning ridges or bridge grating.
Instead of keeping the spacing and height and width of the bumps or grooves consistent, I propose to vary each of these characteristics. By using standard audio sampling methods, ANY verbal message may be converted into a series of digital amplitude values. By duplicating this sequence along the highway, THAT VERBAL SOUND is induced in the tire, which is heard in the passenger compartment by the driver. Psychologically, we are extremely alert to the sound of a human voice, especially in a situation when it is unexpected. Hearing this verbal warning message would certainly focus the alertness of the driver immediately, possibly keeping an accident from happening.
When the word "Warning!" is spoken, it takes about one second. At highway speed, a vehicle travels about 100 feet per second. This means that the bumps or grooves would need to be spread out over a stretch of a hundred feet so the verbal message sounded correct at that speed. This extended space allows roughly one thousand individual bumps or grooves, enough sound detail to make the verbal message quite understandable. It wouldn't be of CD or radio quality, mostly because the relatively large diameter of the vehicle's tires is in contact with several bumps all at the same time, which sort of "smears" the resultant sound.
At higher vehicle speed, the message is heard in a higher pitched voice, and a little more rapidly. At lower speeds, it sounds like a deeper voice and it is said more slowly. Below about 40 mph, the effect is somewhat less. There is less impact on the tire, so therefore the loudness is less. Also, there is even more smearing of the sounds produced, so the message is less understandable.
( http://mb-soft.com/public/othersci.html )
C Johnson, Physicist, Physics Degree from Univ of Chicago