When analyzing roads, intersections, and traffic flow, engineers face a common challenge: vehicles are not all the same. A car, a motorcycle, a truck, and a rickshaw each take up different amounts of road space, move at different speeds, and influence congestion differently. To solve this, transportation engineers use the Passenger Car Unit (PCU) — […]
When most people talk about rush hour traffic, they’re thinking about the frustrating congestion on roads during the morning and evening commute. Transportation engineers use a more technical term for the same idea: peak hour traffic. Understanding how traffic builds up during these busy times is crucial for designing roads, planning intersections, and evaluating new
Traffic Impact Assessments (TIAs) are critical tools that help municipalities understand how new developments will affect local transportation networks. These TIA guidelines provide a practical framework for preparing and reviewing TIAs in municipalities that do not yet have their own standards. The intent is to balance technical credibility with simplicity, ensuring municipalities can review studies
Annual Average Daily Traffic (AADT) is one of the most fundamental measures in traffic engineering and transportation planning. It represents the average number of vehicles that travel on a roadway segment each day over the course of an entire year. Put simply, it is a way to smooth out traffic variations across weekdays, weekends, and
In traffic engineering, the K-factor is a critical parameter used in roadway design and traffic analysis. It represents the proportion of Annual Average Daily Traffic (AADT) that occurs during the design hour, and it allows engineers to size and evaluate roadways for their most critical operating conditions. Trying to calculate a traffic signal warrant? Try
What is an ESAL? ESAL Formula Where: Typical Load Equivalency Factors (LEFs) (based on AASHTO & typical LEFs) Vehicle Type Axles Typical Load (kips per axle) Approx. ESAL per Pass Passenger Car (sedan) 2 2–3 0.0004 Pickup / SUV 2 3–4 0.001 Delivery Van (2-axle, light) 2 4–5 0.005 Single-Unit Truck (2-axle, 6-tire) 2 6–9
Traffic signals are at the heart of modern intersections. Their timing not only dictates how efficiently traffic flows but also affects safety, pedestrian accessibility, and overall network performance. To design or evaluate a signal plan, engineers rely on a set of technical terms that describe how green, yellow, and red indications are distributed across phases
A transportation (travel demand) model is a quantitative framework that forecasts how people and goods move through a region under different land-use and network scenarios. Done well, a model becomes a decision engine: it helps test road and transit projects, pricing policies, and growth plans before spending real money. This guide covers when you actually
Sight distance is one of the most important considerations in road design. It represents the length of roadway visible to a driver, ensuring there is enough distance to perceive, react, and stop safely when encountering obstacles or conflicts. Inadequate sight distance can lead to unsafe conditions, higher crash risks, and poor traffic flow. This reference
Transportation planning and engineering is one of the most dynamic and impactful career paths available today. It sits at the intersection of technology, infrastructure, sustainability, and public policy. If you’ve ever searched “Should I study transportation engineering?” or “Is traffic engineering a good career?”, this guide will help you understand why the answer is a
