Don't take care of car insurance for someone else. When you pay it automatically, they don't see the costs associated with speeding. Instead, make them responsible for the insurance price increase as well as any tickets they get. They will feel the full effects of any bad driving they do. A speed monitoring system fits in a car's diagnostic port. It then relays GPS coordinates and speeding details back to a website. You can set boundaries for how far someone can travel, when they break certain speeds, and when the device is unplugged. These systems can be bought in electronic stores or online and maintained monthly for a small fee. Examples of these systems include MOTOsafety, Mastrack, and MobiCoPilot. Make sure you have the person's permission before tracking them. The simplest idea you can try to prevent speeding in your area is to raise awareness. Plant a sign in front of your house that notes the speed limit and that "90% of people obey it." Have your neighbors help, and have them pledge to reduce their own speeding. This will reduce speeding for a short period of time as people read the signs. Eventually, this effect wears off as the signs become part of the background. Many times residents of the area are the ones likely to ignore signs and pledges. Seeing a police cruiser is enough to slow people down. Think about when there's a large number of speeders in your area or when it's least safe for them, such as when children are walking home from school. You may need to pester the government a bit before they send a car. A police presence costs the government money and the effects are temporary. As soon as the police leaves, people will start speeding again. The government may also install speed detection signs. These signs display your speed as you pass them. They may shame some people into slowing down, but many others will ignore these. Speed bumps are the most obvious road barrier. People must slow down to avoid damaging their car. However, better results come from narrowing the road, such as by making the sidewalks larger, adding stop signs, or adding chicanes (artificial narrowing). Speed bumps can help, but they can also damage cars and feel annoying to you and your neighbors. If you are permitted to park on the street, you can use your car as a barrier. Otherwise, you should not attempt to block the road on your own. The city may also be able to install yellow hazard signs with a message like, "Deaf children at play." People who see this may take more caution as they travel along the street. A continuous surveillance camera will allow you to monitor traffic near your home. Record yourself driving at and above the speed limit so you have a frame of reference for what's too fast. Then, capture clips of speeders. Once you have the clips, you can send them to people or their employers. For example, you may see that your mailman is speeding and send the clip to their boss at the post office. You can also use these clips to prove to your city government that speeding is a problem.

Summary:
Make everyone in your home responsible for car insurance. Install speed monitoring. Raise speeding awareness with signs and pledges. Ask the city for a police presence. Petition your city for road barriers. Install video surveillance outside your home.