Did you know that traffic lights in Australia prioritise vehicles over pedestrians? As a result, many of the stated goals of health, transport and environment policies are undermined. While state and city governments keep reminding us that they want to encourage healthier, greener means of transport and promote walking and biking, in reality, their policies say the opposite. While walking and biking are space efficient, have less of an environmental impact, are healthier, and are safer for everyone involved in the traffic, to achieve these goals, agencies need to reprioritise traffic lights in Australia to redistribute delays at intersections from pedestrians to vehicles.
Planners generally focus on long-term decisions, like land development and infrastructure, but it’s actually the short-term decisions, such as how many seconds of green light you get at an intersection that plays a huge role in shaping the perception of driving or walking from one point to another. This is due to the fact that people care about the time it takes for them to get from one point to another, so they take one route over another, as well as one transportation method over another.
The name of the game is maths. Traffic lights in Australia are delegated by engineers for this reason. However, it also comes down to values and priorities. Since the 20th century, street space has slowly but surely been enclosed and regulated. This, in turn, has limited the privileges and rights of pedestrians, while promoting the privileges and rights of drivers. The key reason for this is safety and efficiency, but not for pedestrians, unfortunately.
In the past, pedestrians could cross whenever and wherever they wanted to. The introduction of traffic control systems prioritised the movement of vehicles at the cost of pedestrians, slowing effective walking around the city. It’s estimated that pedestrians spend about 20% of their time waiting at intersections. As a result, you see more people drive rather than walk to work, or their destination.
Moreover, pedestrians take longer to cross a street than vehicles, simply because they’re slower. As a result, the don’t walk signal flashes before the traffic light turns red. But in many intersections, it’s much worse. The traffic signal can be set to flash green less than to motor vehicles, in order to give vehicles a right-to-left turn without having to yield to pedestrians. There are also adaptive signal controls that extend the green light for cars when they’re detected, but not one for pedestrians, who can’t be detected. For that reason, the average pedestrian coming to an intersection randomly will wait longer than a vehicle. There are a few more factors that guarantee this, such as:
The cycle length represents the time from the start of one green light to the start of the next. Cycle length is generally longer at busier times of day and busier intersections. A longer cycle reduces the number of phases per day, and the associated lost time with each phase, when the intersection isn’t effectively used by any approach. Lost time can’t be reclaimed, so you can understand why many engineers prefer longer cycle lengths if the main goal is to move vehicles. However, long cycle lengths are disadvantageous for pedestrians who stand in the open, exposed to the exhaust emissions of vehicles and the elements. Moreover, people constantly misperceive travel delays, so waiting feels longer than it is.
Traffic signal coordination looks to ensure vehicles get to the traffic signal when it’s green so they don’t have to stop. As a result, vehicles get to move together through what’s called a green wave. So, if the wave is set for speeds of 40 km/h, as long as every vehicle maintains that speed, they’ll get to the next intersection on a green light. This is quite easy to maintain on single roads, but becomes more difficult in complex, asymmetric networks. Moreover, it works against the idea of actuation, as any interruptions of the coordination can change the window in which vehicles come across a green light at a given speed.
Some traffic signals are fixed time, whereas others are actuated, meaning they respond to the presence of vehicles by adjusting the cycle time and phasing. This is done with the help of cameras or sensors on the road. As a result, the signal can stay green for longer or turn red if there are no vehicles. On the flip side, pedestrians need to push a button to get a walk signal. If they arrive a few seconds late, they’ll have to wait for the whole cycle to get a new walk signal. Additionally, you don’t get a longer walk signal if there are more pedestrians. Pushing the button twice won’t make the walk signal longer, and it takes more time for pedestrians to cross the street anyway, and giving pedestrians an automatic phase will delay vehicles, causing more traffic.