Why freeways come to a stop

Even though the road looks smooth, it rattles you and your vehicle like crazy. It has been like this for years. Do they ever plan to smooth this out?

A: Yes. No date has been set yet, but repairs will be coming. We cannot have internal organs needing to be realigned. Q: I have had several frightening experiences when I looked in my rearview mirror just in time to see a driver speed past me along the shoulder of the freeway. Had I been exiting at the same time, it makes me shudder to think what could have happened.

Q: Thieves stole the catalytic converter off my Prius during a few months ago. Parents and supervisors. Road rules. Safe driving tips. Cycling Laws. My car licence Driving is one of the riskiest daily activities that you'll do so preparing yourself and your vehicle is vital. My motorcycle licence Riding a motorcycle is enjoyed by people of all ages.

However, compared to driving other road vehicles, riding a motorcycle can place you at higher risk than others. If you are involved in a crash, the chances of being injured are very high. My heavy vehicle licence The term 'heavy vehicle' applies to the trucks, B-doubles and road trains that transport goods across Australia.

It also includes buses, trams, agricultural machinery, livestock transporters, tankers, grain and delivery trucks and other long and possibly slow moving vehicles on our roads. The following provides information on upgrading your licence to a higher class. Heavy vehicle inspections Heavy vehicle inspections required on change of ownership from Parents and supervisors Supervising a learner driver is a challenging experience. It can also be very rewarding. You'll help a young person develop the skills and attitudes they need to become a safer, smarter driver.

Road rules Is your knowledge of basic road rules up-to-date? Breaking basic road rules contributes to thousands of avoidable crashes in South Australia resulting in injuries and fatalities each year. Safe driving tips Driving involves risk and safe drivers aim to reduce and manage their risk. To learn more or opt-out, read our Cookie Policy. If you've ever driven on a highway, you've probably seen it happen. Traffic slows to a crawl, then stops entirely.

Minutes later, it begins to move again, and then suddenly, you're moving at full speed. The weirdest part: there's no construction, accident, or other possible explanation for the traffic. Why does this happen? As it turns out, a few different groups of researchers have been using mathematical calculations and real-world experiments to try answering this question.

And they think they have the answer. They also have suggestions on how to stop these jams. If there are enough cars on a highway, any minor disruptions to the flow of traffic can cause a self-reinforcing chain reaction: one car brakes slightly, and the ones behind it brake just a bit more to avoid hitting it, with the braking eventually amplifying until it produces a wave of stopped or slowed traffic.

Even when cars leave this traffic wave, though, the wave itself doesn't disappear: it gradually drifts backward, against the direction of traffic. He and others developed the concept of these waves which they call jamitons, because they're analogous to waves in physics called solitons using computer algorithms that simulate driving behavior:.

Japanese researchers have also conducted real-world experiments that come to the same conclusion. In one, they instructed 22 drivers to drive at the same speed Inevitably, traffic waves formed:.

In one sense, it seems reasonable to blame these phantom traffic jams on individual drivers. The models indicate that these jams are more likely to form when people drive as fast as possible, then finally brake when necessary to avoid hitting the car in front of them, triggering a chain reaction.

Another way to think of it, says Berthold Horn — an MIT computer scientist who's worked on the same topic — is to try driving so that you stay halfway between the car in front of you and the one behind you. This will lead to you avoid sudden braking when possible. On the other hand, this sort of behavioral change doesn't totally eliminate phantom traffic jams — it merely makes them less likely to form specifically, it means that a higher density of cars on the road is required for traffic waves to develop.