A Guide to Transportation Planning

Take the US as an example: The benefits of efficient transportation are why the U.S. continues to expand its roads. They have added 300,000 miles of new highways in the last 30 years. In fact, in 2019, the U.S. had a highway network with a total length of 4.17 million statute miles.

As transportation needs continue to develop, it’s essential to be meticulous in both the initial and continuous stages of design - no matter your location around the globe.

What are the four steps of transportation planning?

Step 1: Trip generation

Trip generation analyzes the general infrastructure of current transit in a defined region. It categorizes the frequency of travel in each zone based on origin, destination, and purpose. Individual segments can be further analyzed based on land use, demographics of inhabitants, socioeconomic factors, and other key characteristics.

Step 2: Trip distribution

Trip distribution aims to understand how many trips occur between an origin zone and a destination zone. This can be used to further understand mobility across a region to optimize traffic planning. Calculating trip distribution includes examining macroscopic relationships between locations. Analysis includes relative activity levels at both the origin and destination, travel costs associated with transit, congestion, and improvements to sustainability measures.

Step 3: Mode choice

Mode choice takes into account both trip generation and distribution when assessing mobility. It determines the most popular transportation mode for each transitory route based on region. This is done by computing the proportion of trips taken by each mode of transport within each zone. Mode choice often depends on availability, cost, and social preferences for transit.

Step 4: Route choice

Route choice involves analyzing the preferred travel pathways between origins and destinations within a given area. It assigns travelers to roads towards their destinations. The totality of estimated trips based on origin, destination, and mode are then loaded into the transportation network to understand the impact of route choice on congestion relative to the time of day. This allows planning to include transportation improvements based on existing transit networks. The goal is to minimize travel time and create more accessibility.

What does a transportation planner do?

Transportation planners are responsible for analyzing current patterns and developing a systematic approach to the future of sustainable transport.

They aim to address the demands and shortcomings of current infrastructures. This includes improving infrastructure for all users, including pedestrians and cyclists, while also considering the expected and unexpected environmental and safety issues. A transportation planner's primary responsibility is to increase the overall efficiency of any given area through comprehensive regional transport planning.

This integral perspective requires an understanding of current infrastructures, as well as the projected growth and evolution of a city, town, or region. Some of the primary responsibilities include:

• Recommending transportation improvements and solutions to ongoing problems, such as congestion, vehicle emissions, inaccessibility of public transport, etc.
• Working to decarbonize transport networks for future sustainability.
• Enhancing user safety within the transportation system.
• Assessing the impact of recent or anticipated building developments. This includes transport systems, housing, or corporate structures.
• Designing efficient research methods and survey techniques.
• Modeling traffic flows using mathematical techniques.
• Running simulated computer applications to determine the impact of recommended transportation improvements.
• Analyzing and interpreting data.
• Preparing reports and publications to share data with policymakers and city officials.
• Giving presentations about proposed transportation improvements and regional plans.
• Acting as the subject matter expert during public inquiries.
• Staying up to date and knowledgeable about ongoing government transport and planning policies.

Depending on the regional requirements, transportation planners can be employed at either a public or private level. At either level, their roles remain vast and varied.

What tools do transportation planners use?

Transportation planners spatially analyze various regions to understand current challenges. They’re then tasked with creating action plans that improve travel information, accessibility, public transport, and the overall design of infrastructure. Plans need to be tested to avoid wasting time and money on inefficient construction. 

For ongoing analysis and testing purposes, transportation planners have a variety of tools available, including:

Traffic simulators

Traffic simulators mimic complex vehicle interactions on a microscopic level. It can vary the model demand, supply, and behavior in detail so transportation planners can determine the most effective long-term strategies for change. Using PTV Vissim, the world’s most advanced and flexible traffic simulation software, planners can benefit from detailed, realistic simulations with seamless integration and flexibility. It provides a detailed view of the traffic flow and its impacts.

Traffic planners

Alongside the traffic simulator, planners need a tool that provides all of the traffic information of a region in one, easy-to-use software. PTV Visum enables a holistic overview of the traffic situation to help forecast and measure the effects of development and traffic planning. This software integrates the four-step travel demand model into a stable test environment. Traffic planners allow for testing multiple what-if scenarios for different modes of transport such as private, public, shared, and autonomous vehicles.

Transportation Demand Management Evaluation Tool

This data collection tool is used to capture the real-time effectiveness of a region’s transportation behavior, demands, and shortcomings. Useful information can be gleaned by capturing the relevant data, which is fundamental to improving infrastructures going forward.