Editorial
Imagine the clock just hit 4 PM on a sunny Friday afternoon. It is the end of an exceedingly long work week, and you have worked hard to earn your weekend to relax and unwind, spend time with family, or prepare for the following week. However, there is one problem standing in the way of that well-deserved break: rush-hour traffic.
The word often used to describe the traffic buildup is congestion. Congestion, as defined by the US Department of Transportation, is “an excess of vehicles on a portion of roadway at a particular time resulting in speeds that are slower—sometimes much slower—than normal or "free flow" speeds”. (Ahmed et al., 2023) Congestion is caused by many varied factors that fall under two main categories, physical capacity issues and traffic-influencing events.
Physical capacity issues, also known as bottlenecks, are areas of the roadway where traffic with higher capacity flows to sections less equipped to handle traffic capacity. These areas include roadway features (or flaws) such as lane drops, entrance and exit ramps, and freeway interchanges. When examining the places where congestion is high, one or more of these bottlenecks are always at the root of the problem.
Traffic-influencing events are what I would consider the uncontrollable things we encounter on the road. These events include vehicle accidents, inclement weather, work zones, and other unique events like roadway debris or animals near the road. All these things have one thing in common: When a driver encounters one of these things, their brake lights illuminate instantly. Their reaction, while sometimes necessary, can cause a traffic snake that leads to congestion.
​Now that we have identified the causes of congestion, you might wonder how we can solve the problem. Ramps and interchanges are essential to how our roadways function, and we cannot control the weather or when accidents occur. This problem has many different variables and thus requires multiple solutions to address each unique part of the congestion issue facing our roads today. Adding lanes to increase capacity can be incredibly expensive, and they will not solve the problem of traffic influencing events, and the solution for severe weather may not help avoid congestion when other issues arise.
One way we found to cover a range of the issues we identified is a concept called Flex Lanes. This concept has key components that help curb congestion before it becomes an issue. The first piece of the puzzle is the flex lane itself. It is an extension of the shoulder, slightly narrower than a standard lane. It can be opened and used as a lane for traffic as needed. The way that drivers will know when this lane is open for use brings us to the next component, which is the use of digital signs over the roadway. These signs can serve multiple purposes, one of those using symbols to indicate which lanes are open and which are closed. The signals can also display different speed limits, which can display variable speed limits for each lane. They can also indicate to drivers that they need to slow down due to traffic ahead when the signs will display speed limits that decrease gradually so drivers do not have to brake aggressively, behavior that can lead to accidents. Finally, the signs can display horizontal arrows diverting traffic away from a lane that has a cause of congestion. For example, if there is an accident in the right lane, traffic would be directed to the right two lanes of a three-lane highway ahead of the accident to reduce the congestion caused by the accident.
In addition to physical solutions that we have found to be effective, we believe that some of the issues can be tackled by looking at the drivers themselves. Improving driver education and emphasizing practical driving skills in driving courses, such as driving on the freeway and during inclement weather could lead to an immeasurable impact on the congestion issue, we experience during traffic-influencing events. Today, most driving courses and tests involve a short road test on local roads. They do not even begin to cover the scope of what a driver could encounter on the road, and thus drivers who encounter something they have not experienced yet will understandably be hesitant. We need to increase the barrier for entry to inexperienced drivers, including mandated hours driving in inclement weather and the dark, and a test that involves highway driving to ensure that drivers are prepared for what they will encounter on the road.
There are an endless number of variables that a driver can encounter on the road, and it would be unrealistic to attempt to eliminate all traffic from our roadways. A traffic accident involving more than two or three vehicles will never end without congestion. However, the solutions that we have found are aimed at reducing the likelihood of traffic buildup and lessening the effect of that congestion when it inevitably does arise. If states adopt some of these changes to their roadway infrastructure and driver education requirements, we may see some improvements during rush hour and bring a bit of flow back to our roads.