Ask The Traffic School Instructor: Speed Limits
September 24, 2014
Question: Do speed limits reduce traffic accidents?
Answer: No, speed limits by themselves can’t save lives. However, drivers who obey the posted speed limits do save lives. Let’s look at the purpose of speed limits and then, at why speed is dangerous.
According to the National Highway Transportation Administration (NHTSA), approximately one-third of all highway traffic deaths are directly due to speeding. Speeding means either going faster than the posted speed limit or traveling too fast for conditions.
What’s the purpose of speed limits?
There’s a popular belief that speed limits are just a way for governments to raise income by handing out traffic tickets but that’s not the case. Speed limits are determined by traffic engineers and set by local or state governments. No one likes traffic jams so, when trying to determine a speed limit, traffic engineers are actually trying to determine the highest safe speed that will allow traffic to move freely. In order to do this, they have to look at a lot of factors including; size of the road, number of lanes, curves, hills, whether the roadway passes through a school zone, shopping district, etc.
Taking all of those factors into consideration, once a speed limit is set, it is the maximum speed allowed during ideal conditions. Ideal conditions mean clear visibility and dry roads. When there is heavy rain, snow or fog, it’s up to drivers to adjust their speed according to conditions. Even if a driver is traveling at or below the speed limit, it’s still possible to get a speeding ticket for driving too fast for conditions.
Why is speed a problem?
The higher the speed, the less time a driver has to react to an emergency situation ahead. It takes between 1 to 1.5 seconds for a driver to react to an emergency situation. That means a driver obeying a speed limit of 45 mph will travel approximately 99 feet before he or she can fully react. A driver traveling 10 mph over the speed limit will travel more than 121 feet in the same amount of time. A lot can happen in that amount of space.
Laws of Physics
The laws of physics come into play also. A basic law of motion states that an object in motion tends to remain in motion – in a straight line. A driver driving too fast in a curve stands a good chance of losing control and running off the roadway because, due to the laws of motion, it’s physically impossible to keep the vehicle on the road. Physics also come into play in a crash. The higher the speed, the greater the crash forces will be.
Reducing traffic Jams
Believe it or not, if everyone were to obey the speed limit and keep a safe following distance between their vehicle and the vehicle ahead, traffic would move much faster and more smoothly. Traffic jams are caused by drivers who are driving too fast and then hit the brakes when they approach a vehicle ahead. This causes traffic behind to hit the brakes and a traffic jam is the result.
You won’t get there any faster by speeding and yes, obeying the speed limit saves lives!
Ask The Traffic School Instructor: Reducing Traffic Jams
September 17, 2014
Question: What can be done to reduce traffic jams?
Answer: Traffic engineers are always looking for ways to reduce traffic jams but those solutions usually involve adding extra lanes or exits. If you live in a place where these types of road improvements have occurred, you’ve probably noticed that it didn’t take long for the traffic jams to return. It seems like adding extra lanes just draws more traffic but that actually isn’t the case.
Believe it or not, even with the same amount of traffic, individual drivers can make a big difference when it comes to reducing traffic jams. To do that, you first have to understand how traffic jams start. It’s not really the volume of traffic but the way people drive in those situations that create the traffic jams.
Traffic jams begin with what are known as traffic waves. Generally, a wave starts when a driver nears a slower driver ahead and hits his brakes. Once his brake lights come on, the driver behind hits her brakes and so on and so on and so on…… The driver in the front hasn’t been affected by the wave but traffic a quarter mile behind is now coming to a stop. This wave effect has also been compared to putting a kink in a water hose.
Traffic engineers understand this effect and, in some places, are trying to correct it in a way that sounds counter intuitive. In Atlanta and Washington State, traffic engineers are trying to prevent traffic jams through the use of variable speed limits on the interstate. By watching video monitors in a command center, when they see traffic waves start to build, they’ll adjust the speed limit via electronic speed limit signs. However, instead of increasing the speed, they’ll try to slow down the traffic behind. By slowing traffic behind, in some cases down to 35 mph, they hope that the wave ahead will have time to break up and move on. By allowing the wave time to break up, fewer cars behind will hit the brakes, causing an even longer wave. By slowing traffic, they hope to keep it moving instead of bringing it to a halt. Moving along at 35 mph is better than not moving at all. It’s too early to tell if it will work in Atlanta but it seems to be working quite well in Washington.
But we don’t have to wait for traffic engineers to solve the problem. Individual drivers can take action to stop traffic waves by simply allowing a longer following distance between them and the cars ahead. Even if traffic enters the lane ahead of you, if you back off slightly by taking your foot off the gas, you’ll notice that, while you may be going just a little bit slower, you’re still moving. It also has the effect of eliminating traffic waves behind you. If you try this, hopefully, you’ll find, just as the driver who created the video below has found, that a single driver can make a big difference when it comes to reducing traffic jams. Driving on the interstate isn’t a competition, it’s a cooperative effort!
Kids In Cars Put In Danger By Parents
September 16, 2014
One in five parents put kids in cars in danger by “bending the rules” according to a survey conducted by Safe Kids Worldwide and funded by the General Motors Foundation. In the online survey, parents admitted that, when carpooling, they sometimes bent the rules by allowing kids to ride without a booster seat or even without seat belts.
According to Safe Kids, “Sixty-one percent of parents say they notice other carpool drivers bending the rules. Safe Kids research also shows that one in four parents report they don’t buckle up their children on every ride.”
Even on a short trip, the dangers of a crash are high. Most car crashes happen within 25 miles of home and at speeds under 45 mph. The reason for that is simple; your chances of being involved in a crash close to home are greater because that’s where you drive most often.
School age children should be belted into a booster seat seat until they are big enough to wear a seat belt properly. Safety experts say that kids should remain in a booster seat until they are at least 4’7” tall and weigh between 80 and 100 pounds. For most kids that’s between 9 and 11 years of age.
According to the National Highway Transportation Safety Administration (NHTSA), motor vehicle crashes were the leading cause of death for children age 4 and every age 11 through 14. They are the second leading cause of death for ages 5 through 10. NHTSA data shows that, “among passenger vehicle occupants 5 and older, seat belts saved an estimated 12,174 lives in 2012. If all passenger vehicle occupants 5 and older had worn seat belts, 15,205 lives (that is, an additional 3,031) could have been saved in 2012.”
Even on short trips, kids in cars need to be buckled into a child safety seat appropriate for their age. Parents who carpool should never take more children than the number of seat belts available in the vehicle. Carpooling parents should also arrange to swap out car seats and booster seats.
Don’t place yourself in the position of a parent who says “If only I had….”
For more information, read: STUDY REVEALS 9 OUT OF 10 PARENTS MOVE THEIR CHILD FROM BOOSTER SEAT TO SEAT BELT BEFORE THEIR CHILD IS BIG ENOUGH
Child Passenger Safety Week Sept. 14-20
September 15, 2014
This is National Child Passenger Safety Week and it’s a good time to remind parents or those who care for children, about the proper way to care for a child while driving. When it comes to child safety seats, one size doesn’t fit all and it’s important to understand how to choose and install the proper child seat according to your child’s age.
According to a survey by the National Highway Transportation Safety Administration (NHTSA), these are the most common mistakes made by parents when installing and using child safety seats and booster seats:
- Wrong harness slot used – The harness straps used to hold the child in the car seat were positioned either too low or too high;
- Harness chest clip positioned over the abdomen rather than the chest or not used at all;
- Loose car seat installation – The restraint system moved more than two inches side-to-side or front to back; anything more than one inch is too much.
- Loose harness – More than two inches of total slack between the child and the harness strap; there should be no slack.
- Seat belt placement was wrong – Lap belt resting over the stomach and/or shoulder belt on the child’s neck or face.
Both NHTSA and SafeKids recommend the following steps listed on the Safe Kids downloadable checklist:
- Right Seat. Check the label on your car seat to make sure it’s appropriate for your child’s age, weight and height.
- Right Place. Kids are VIPs, just ask them. We know all VIPs ride in the back seat, so keep all children in the back seat until they are 13. Doing this, along with correctly using the appropriate child restraints, greatly reduces the risk of injury.
- Right Direction. You want to keep your child in a rear-facing car seat for as long as possible. When he or she outgrows the seat, move your child to a forward-facing car seat. Make sure to attach the top tether after you tighten and lock the seat belt or lower anchors.
- Inch Test. Once your car seat is installed, give it a good shake at the base. Can you move it more than an inch side to side or front to back? A properly installed seat will not move more than an inch.
- Pinch Test. Make sure the harness is tightly buckled and coming from the correct slots (check manual). Now, with the chest clip placed at armpit level, pinch the strap at your child’s shoulder. If you are unable to pinch any excess webbing, you’re good to go.
Many parents don’t realize that child safety seats have an expiration date. The plastic and synthetic materials used to make the seat’s body and straps can break down over time when exposed to the high heat and sunshine in a parked car. It’s not a good idea to use a hand-me-down car seat for younger children.
There are several good websites that provide information on the proper selection, installation and care of child safety seats. For information about:
- Advice on child safety in and around cars, visit the Insurance Institute for Highway Safety (IIHS): http://www.iihs.org/iihs/brochures/keeping-children-safe
- IIHS ratings on booster seats, visit: http://www.iihs.org/iihs/ratings/child-boosters
- Where to find a car safety seat inspection station near you, visit: http://www.seatcheck.org/
- Child safety seat laws in your state: http://www.iihs.org/iihs/topics/laws/safetybeltuse?topicName=child-safety
Interactive Map Shows Biking And Jogging Routes Near You
September 15, 2014
A new, interactive map allows anyone in the country to see the most popular biking and jogging routes in their area. The map was created by Strava, an app that allows bikers and joggers to track their routes and analyze their performance. The map can also alert drivers to areas where they might expect heavier than normal concentrations of bikers and joggers. Read more: This interactive map shows the most popular running and cycling routes in your city