Understanding the Basics of Traffic Engineering Design

Understanding the Basics of Traffic Engineering Design

What is Traffic Engineering Design?

To understand a traffic engineering design, you first need to understand what a traffic engineer is. Simply put, a traffic engineer is a qualified engineer who studies, analyzes, and develops road projects.

Traffic engineering design is the final of those three options – developing. It is a traffic engineer’s job when designing to create a transportation system that is safe and efficient. Taking a variety of factors into consideration – such as needed intersections, surrounding buildings, and the volume of traffic in the area – a traffic engineer will design a transportation system that is both efficient and safe.  

Key Elements of Traffic Engineering Design

Traffic Flow

When a traffic engineer is designing a transportation system, they need to understand the volume of traffic in the area and consider how their new or improved roadways will handle it. Parts of the design like signs, signals, extra lanes, and speed limits will all impact traffic flow. The goal is to keep traffic flowing efficiently and safely and to avoid congestion.


Safety is the number one concern for traffic engineers. They work diligently to understand the needs of the area they’re designing to ensure that everything is built to optimize safety for pedestrians as well as drivers. They will add proper signs, signals, and extra lanes to ensure traffic is controlled and safe as it moves through the area.


When designing a new transportation system, a traffic engineer’s second concern is efficiency. They’ll either collect their own data or use data from a traffic study of the area to determine traffic volumes and behavior at different times of day, as well as the causes of certain traffic behavior like delays. With a combination of roadway design, speed limits, lane additions, and safe intersections, a traffic engineer can create an efficient system that reduces travel time for all drivers through the area.


With efficiency as a traffic engineer’s second priority, it makes perfect sense that sustainability and traffic design can easily work together. By reducing travel times and keeping traffic flowing, a vehicle’s emissions will be lowered when using a well-designed system.

Traffic Engineering Design Process

A traffic engineer’s design process will first begin with collecting or analyzing previously collected traffic data on the area they’re designing for. Using this information, they will then begin to determine what needs to be included in their traffic system. Usually, the first thing to be decided is the number of standard driving lanes that will be included. This is determined using a ratio of traffic volume to capacity. They will then decide if any auxiliary lanes will be needed, such as left or right turning lanes. This is determined using the amount of visibility and traffic flow through the intersection in question.

The intersection will also need to be designed, and the traffic engineer choosing whether the intersection will be controlled through 2 or 4-way stops, traffic signals, or a roundabout. It is at this time that the engineer will also decide how the auxiliary lanes – if there are any – will be controlled. Finally, pedestrian traffic will be considered, and the engineer will determine if walkways and walking signals need to be added.

After everything has been decided, the traffic engineer will need to put all of the pieces together and evaluate the system as a whole to ensure it runs safely and efficiently.