The Untold Reasons for Traffic Congestion and Pollution in Our Cities and Towns

Part 1: They Count Vehicles, Not People

In Sri Lanka, the primary indicator used for measuring the traffic flow on roads is Level of Service (LOS) and Vehicle Hours of Delay. These are indicators used for assessing the performance of a road network based on measurements like vehicle speed, density, congestion, etc.

However, most transportation and urban planning experts around the world now agree that ‘LOS’ and ‘Vehicle Hours of Delay’ are not effective indicators to measure the effectiveness of passenger transportation.

The primary issue with these indicators is that it equates the movement of vehicle volume and speed to the effectiveness of the transportation system. However, this could be misleading due to the following reasons.

• The primary objective of passenger transportation is to move more people as effectively and efficiently as possible to their destinations.

• Automobiles carry one or two passengers most of the time, while public transportation, such as buses carry 100s of passengers.

• Automobiles occupy a much larger road space while transporting relatively a smaller number of people, thus very space inefficient.

In summary, public transport, such as buses, can transport many passengers, while automobiles transport few while occupying a large road space per passenger.

Therefore, if the transportation network is designed to move people more effectively and efficiently, we need to prioritize public transportation first and foremost. But to do that, first the tools of measurement need to be changed to measure the movement of people, instead of vehicles. There are already such indicators available and used worldwide, including Accessibility Index, Vehicle Miles Traveled (VMT), and People Hours of Delay.

Part 2: Do you know the difference between streets and roads? And how it affects our everyday life?