 folks heading downtown this morning, I'm afraid there's good news and bad news. The good news first. You've got a nice sunny morning out there. Now the bad news. There's an accident blocking the right lane of the downtown expressway near the Main Street Overpass with traffic backed up all the way to the Beltway. Meanwhile, you folks on the east side bypass can expect the usual delays in the usual places and there are reports that traffic is already slow for half a mile approaching the Elm Street on ramp. Traffic is also heavy around the south side. The morning rush. Traffic already backed up with no relief in sight. Tempers flare. Cars over heat. The safe and efficient movement of traffic along our urban freeways systems is serious business. A serious concern that affects every community. Nationwide, urban areas are experiencing travel growth of three percent per year. Our ability to build new freeways or widen existing ones has not kept pace with this increasing demand. What results is congestion. Congestion is a direct result of the nature of supply and demand. Traffic engineers describe the supply in terms of the freeways capacity. During off-peak periods when freeway traffic is lightest, the freeway has a temporary excess of capacity. Vehicles are spaced quite far apart and entering vehicles are readily absorbed into the traffic stream. As rush hour approaches, however, more and more motorists choose to travel the freeway using more and more of its capacity. Vehicle speeds begin to drop as the freeway becomes more crowded. When rush hour arrives, virtually all of the freeways capacity is being used. Vehicles are spaced very close together and there are only a very few usable gaps available in the traffic stream. The key word here is usable. Keep in mind that most of those inviting open spaces between vehicles are actually safety buffers, which drivers need in order to stop quickly without endangering other motorists. Obviously, under these conditions, any disruption to the traffic stream, such as an impatient driver forcing his way from a ramp into a freeway lane, will cause a ripple effect among the vehicles already on the freeway. If this occurs at the wrong moment, like the straw that broke the camel's back, traffic flow will break down into the all-too-familiar bumper-to-bumper stop-and-go crawl. It all seems so simple when we talk about the problem, so easy to identify. Too many cars, too many people, all trying to get to work or get home at the same time. It's the solutions that aren't so simple. One of the things that we're always looking at is ways that we can make a freeways work better and more effectively and carry more people without going into massive construction projects. Ramp metering is one way that we have found to be particularly effective in terms of making the freeways work a lot better and carry more folks. Ramp metering is simply a concept of controlling the number of vehicles that reach the freeway and the time at which they reach the freeway in order to preserve the capacity of the freeway. Well here in Denver, we got more and more traffic and we weren't able to keep up with additional freeways, so we needed a strategy to try to balance off the additional growth to try to keep the freeways running at a decent level of service. In other words, keep it from going to a stop-and-go condition as much as we could. Ramp metering works very well. We find it a very effective strategy in trying to improve the efficiency of the freeway. In Denver, we're seeing an increase in capacity on the freeway of approximately 10 to 15 percent over the pre-metered condition, so we're actually getting more cars through at a faster rate and in a safer condition. In the Twin Cities, in the late 1960s, we started experiencing recurrent congestion on several freeways and to mitigate this congestion, we started experimenting with ramp control signals and our initial studies were very successful and this led to an expanded program. On I-35W, about a 17-mile section of freeway, we had travel times of about 30 minutes before we started metering. After the metering was activated, we cut that to about 22 minutes. Without ramp metering controls, the freeway can easily become overcrowded. Unmetered traffic entering the freeway can cause backups. Forcing their way into traffic, drivers can cause accidents. Ramp metering smooths the merging process, allowing vehicles to enter the freeway in an efficient, orderly fashion. In this way, the capacity of the freeway can be preserved. The operation of freeway ramp meters is simple and direct. All the instructions drivers need are clearly printed on signs at proper viewing height. The metering signal, like any other traffic signal, regulates the right of entry among competing streams of traffic on intersecting roadways. Ramp metering signals typically allow only one or two vehicles to pass during any one green indication. In some cities, provisions have also been made for buses and carpools in separate lanes. The ramp meter signal is placed along the entrance ramp at a point where traffic can easily accelerate to freeway speed after having been stopped by the signal. It's placed far enough down the ramp to allow maximum space for the storage of cars waiting to get on the freeway. Typically, a ramp meter is controlled by a computer that accepts information generated from vehicle sensors embedded in the freeway and in the entrance ramp. As the traffic on the freeway increases, the information passed to the computer triggers a response which slows the frequency with which vehicles on the entrance ramp are allowed into the freeway traffic. In some systems, each metered ramp is also connected to a main computer that monitors and coordinates the entire system. At this central location, engineers can adjust or override the mechanical system should conditions require such action. This is the operation center for the LA region. Now what we see here in the background is our display panel. You see a series of red, yellow and green lights. The data is coming in from the field. The sensors in the pavement are recording that data. It's transmitted in here and we do two things with that data. One, we drive this board and with that series of red, yellow and green lights we show the congestion conditions on the freeway. The second thing that system is doing is continually comparing the data from one set of sensors with the data from the downstream set of sensors. And if there is a great difference in that traffic volume, then our program recognizes that and the red light at that location flashes. We can also take over the ramp metering rates from this room. We can do that on a regular basis if we want to or we can do that to meet the needs of an incident. Well here in Denver, we run a demand responsive system or traffic responsive system where we monitor freeway conditions, the main line conditions and measure the ramps according to what we find on the main line. We also have a central computer system which allows us to adjust for localized conditions throughout the system to try to balance the system out. On our ramps, we use a series of detectors, one to determine if there's a car ready to be metered on the freeway, a detector to determine that the car has been metered properly, but a feature that we have is called a Q override system. In other words, when the ramps tend to back up that may cause a problem on the cross streets, we will meter the freeway ramp faster than we normally would to keep that from occurring. When traffic backs up onto surface streets, several alternatives are possible. Drivers may choose to remain on the surface street or try another ramp. Experience however shows that many drivers simply change the time of their travel to avoid ramp delays. In many cities, ramp metering has improved freeway travel so much that there has been a noticeable reduction in traffic on parallel surface streets as motorists move to the freeway instead. Another alternative is the system used in Denver and other cities where there are no parallel surface streets. The metered rate can be adjusted as the system senses an access backup, changes the timing cycle on the signals, and allows more rapid access to the freeway. While this may allow the freeway to become congested, the duration of freeway congestion will still be shorter than it was without the meter. When morning and evening peak traffic periods put thousands of people on the freeway system all eager to reach their destination quickly and without inconvenience, the need for safety is paramount. Our evaluation studies have shown that ramp metering is very effective in terms of improving freeway safety. Our largest system on I-35W has resulted in a reduction of about 120 accidents per year and a reduction in the accident rate of about 38%. We've made many studies as we have implemented projects over the years taking a look at the before and after conditions as far as accidents are concerned. In every case there has been a significant reduction in accidents associated with the ramp metering. What we found in Denver is that we did trade off accidents from a more severe type to a less severe type accident. By allowing the vehicles to merge more efficiently on the freeway system we eliminated a lot of the side swipe type accidents and rear end type accidents which were occurring at the gore and there were we did see a few increase in minor accidents of the rear end type on the ramp themselves. As we've heard, congestion on the freeway has a direct impact on the frequency of accidents. Less congestion, more efficient operation, fewer damage and injury accidents to travelers. Ramp metering can substantially reduce merging accidents on controlled ramps. As the freeway operates more efficiently, metered flow of traffic allows enough space and enough time for drivers to leave the ramp and enter the flow of traffic without endangering themselves or the traffic already on the freeway. When a system of ramp meters is announced in a community it may not be long before the voices of the local residents can be raised to a shout. Not everyone understands that ramp metering provides a safer more efficient use of our freeway system. Many are concerned that ramp metering won't be equitable, won't be fair. Well I think any type of improvements that you get into you have to look at the idea of what's fair and who gains and who loses but I think part of the the answer to that is that you have to explain to people that overall although they might have to stop for maybe a minute or so and wait before they actually get on the freeway that once they do get on the freeway they're going to be able to move a little faster and they're going to pick up that time plus gain some. Although drivers who begin their journey out beyond the installed ramp meters have unrestricted access to the freeway, careful monitoring of traffic flow and analysis of freeway capacity can ensure equitable access for all travelers. One of the first things we recognized in Los Angeles was the need to inform the public of this new device, this new control on their method of travel and when and where they wanted to travel. So we put in place a public information approach informing the public at large, the motorist out there, informing the elected official, informing the traffic engineering profession at large, explaining to them what it was we were trying to do. It wasn't simply that we wanted to control their lives, there was a reason for this control and that was to try to maintain some efficiency on the freeway and to bring that about. In the Twin Cities area our public information efforts helped prevent a lot of negative reaction by the motorists. We had a few complaints when ramp meters would get stuck red but overall we had a very favorable response. I think the most important thing in developing a public awareness campaign for ramp metering is to make sure that the public is brought on board throughout the entire process as well as the local elected and staff officials. If they are brought in at the very end there may be considerably more resistance than if they're brought in through the entire process so that they're aware of the goals that ramp metering is trying to achieve. Because the Los Angeles County Transportation Commission is a public body, anything, any decision that is made is done through the public process. There are a number of public meetings that take place and anyone that has a concern about a project has an opportunity to come in to express their concerns. We also try to be very tuned into and responsive to communications that we get phone calls, letters from people that might have concerns and either to go out and try to explain the situation why we're doing something a certain way or to figure out what their problem is and how we can perhaps take care of a solution while we're taking care of everybody else. The installation of ramp metering devices in an existing freeway system and the inclusion of ramp metering in the design of a new freeway can provide significant benefits for the community and its people. As we have said ramp metering smooths the process of traffic merging from ramps, reducing delays and stoppages at ramp ends, reducing accidents significantly. And because a ramp metering system can adjust to changes in traffic flow, it helps maintain a proper balance between demand and capacity and helps ensure a fair distribution of freeway access times among all ramps. In short, ramp metering allows a freeway system in peak traffic periods to operate at capacity and that means efficiently. Though not a cure-all for the complex problems of moving people in and out of an urban environment, ramp metering is a proven way to maximize the capacity of a freeway system. Short of adding lanes or constructing new freeways perhaps no other improvement can contribute as much to the safe and efficient movement of traffic as a carefully designed and well-operated ramp metering system.