So when we look at the range of the thoroughfares that can be used in the design of smart communities, smart growth neighborhoods. Most are designed to be equally available to pedestrian, bicycle and automobile traffic, which is different from the more standard type of community design today. And a big part of that is achieved through traffic calming, approaches that combined to develop the design speed on the roads without the use of speed bumps and other disruptive devices. Things like complex intersections, tight corner, and on street parking. And we'll go into each of these a little more in this module. One thing to avoid, if possible, is one way in multilane thoroughfares. They're not walker friendly, but there are a rich variety of available thoroughfares that can be organized according to the context of the neighborhood. And these include avenues and boulevards, streets, roads, alleys, lanes, and passages, and we'll go into each of these in this module. There's also different road geometries that will explore free flow, slow flow and yield flow. So, that's a summary of some of the things we'll be covering as illustrated here. There's a variety of ways to address that, and there's varying circumstances under which these applications would be made. But I guess the key point here is it's looking at a balance of pedestrian, bicycle and automobile traffic and of course, also public transportation. When considering the design of the streets in the neighborhood. So let's first look at complete streets, and again it's a balancing, but when you consider that streets are really one of the primary public places, or they can be. And there's a lot of activities that can go on along a well designed and planned street, can become the center of a civic activity in the community. Streets can become a gathering place, but in order to achieve that requires an interdisciplinary participation by engineers, planners, architects, landscape architecture and utility companies. In making all the aspects come together, when streets become a pleasant place to be during the year, during the day, during the week where people are likely to leave their car at home. And take to the streets by bike, public transit or walking, so, this is one of the things we'll be looking at, an important aspect of any smart development activity. Another aspects of streets is the design speed or, and that doesn't mean the speed limit, but designing the street in a way that it promotes lower speeds. And that can be achieved in a number of different ways, and certainly speed is critical to pedestrian safety and comfort. The example is of a pedestrian collision with an automobile at 20 miles per hour, an average has a 95% chance of surviving. But you compare that to a 40 mile hour collision, and there was only a 10% chance of surviving. So from a safety standpoint, speed on local streets is important, even though most local streets may be designed to allow vehicle operation at much higher speeds. The challenge is how to redesign those streets to induce slower speeds. The most effective way to control vehicular speed is by narrowing lane widths and also by avoiding long straightaways, where there's the natural inclination to increase speed. But these factors can be combined to, automatically regulate of vehicle speed to what's called the design speed. That's the desirable speed level for the neighborhood. Often the design speed is 25 mph or less. In fact, in many British cities now, they require 20 mph or less. Another aspect is using complex geometries, contrary to what might be an intuitive is that the accident rate at complex geometry intersections, is lower than more traditional right angle type intersections. So this tends to calm traffic, because they're more complex drivers will slow to make sure they're following the right path through the intersection. And as a result, these complex intersections have a much lower accident rate. Studies have shown that some of our nation's most complicated intersections, especially those without signalization, experienced the lowest accident rates. The other thing about complex intersections is that they create a self policing environment, particularly from a speed control standpoint, which is safer, both for the drivers and the pedestrians. And also by the use of these kinds of devices, there is less need to do more aggressive measures, such as speed bumps, ball bouts, and so forth which are disruptive to the drivers.