Traffic is a huge problem in most cities. There are some cities that are taking innovative steps to manage traffic. Some cities have decided to use price discrimination to better allocate roads to drivers during peak hours. This is relatively easy to do with devices such as EZ pass and other sorts of sensors. However in densely populated cities, there are often other factors which effect traffic negatively.
In the US Jaywalking is a common. One of the reasons people decide to jaywalk is that the costs of interrupting traffic, such as the probability of being hit times the damage from the injury, or the probability of being seen and fined by a police officer are both quite low. In Japan, they deal with jaywalking by using social pressure. In Japan nearly everyone does not obeys the law and does not jaywalk, regardless of time of day or place. It could be on a street at 2:00am, no cars, and no one else around, but Japanese will still wait for the light to be green before crossing. Additionally, it is custom in Japan to stand to the right on an escalator if you are not in a rush, while walking up the left side must be done briskly.
In Shenzhen China, jaywalking is a problem where social pressure does not seem to have much effect. The cost of policing the streets with police officers is high and would likely have little effect due to the large and dense population, so the Chinese have addressed the problem with a few novel devices. The first is the traffic barrier, around all large intersections in Shenzhen there are high gated barriers combined with under ground tunnels or above ground walk ways to cross to the other side. The barriers increase the cost of jaywalking for everyone but Olympic high jumpers. The under ground tunnels or above ground pedestrian bridges provide a safe alternative to playing frogger in the street.
While these devices are expensive, in terms of both the lives they save from not having to jaywalk, the time it saves by not waiting for a light, and the savings you get from not having pedestrians struck in the road, and the reduction in police force necessary are all positive benefits that come from the Chinese bridge and fence solution. In the future, smarter cities will have escalators installed on these crossing bridges to speed up traffic, making this solution even better.