The Problem with Traffic Congestion

What is congestion?

• Road users: a road is congested when car speed falls below the usual level. 
• Engineers: a road is congested when more vehicles try to use it than it is able to carry.

What is the cost of congestion?

• extra driving time
• unexpected delays
• stressed drivers 
• missed appointments
• more fuel used 
• added cost
• higher vehicle emissions. 

The Transport Agency tries to reduce major congestion where possible. 

How is congestion managed? 

There are many ways to ease congestion, including: 

Demand management – Reducing the number of vehicles on a road at any one time. This can be done by: 

• getting people to use public transport 
• travelling during non-congested hours
• tolling parts of the road.

Driver information systems - allows drivers to make decisions about their route and time of travel. 

Build more lanes so traffic is less congested -This is very expensive because the traffic peak lasts only a short time each day, so the extra lanes would be unused most of the time. 

Better use of the road space you already have – Using smart tools such as:

• incident detection systems - keep traffic moving smoothly and help clear incidents quickly
• Information and control systems - let people know of traffic conditions and manage traffic flows during incidents or congestion. 

Ramp signals - A traffic light at the end of an on-ramp directs traffic to enter a motorway and then merge with the mainline flow. The speed of traffic on the motorway and motorway travel times are improved with ramp signals. 

High occupancy vehicle or bus lanes - encourage people to carpool or get the bus which means fewer vehicles on the road.