How can traffic simulation models evaluate the impact of land use changes?

1 What are traffic simulation models?

Traffic simulation models are computer-based tools that represent the movements and interactions of vehicles and pedestrians on a network of roads, sidewalks, intersections, and transit facilities. They can simulate different levels of detail, from macroscopic models that aggregate traffic flows and speeds, to microscopic models that track individual vehicles and drivers, to mesoscopic models that combine both approaches. Traffic simulation models can also incorporate various traffic control devices, such as signals, signs, and roundabouts, as well as behavioral factors, such as route choice, mode choice, and trip generation.

2 Why use traffic simulation models?

Traffic simulation models can help you answer questions such as: How will a new development affect the traffic volume and delay on a corridor? How will a road closure or a lane reduction impact the travel time and reliability on a network? How will a transit expansion or a bike lane installation influence the mode share and the emissions on a region? By using traffic simulation models, you can compare different land use scenarios and analyze their impacts on various performance measures, such as travel demand, capacity, level of service, safety, accessibility, equity, and environmental quality.

3 What types of traffic simulation models are available?

There are many traffic simulation models available, each with its own advantages and drawbacks. VISSIM is a microscopic model that can simulate multimodal traffic, including cars, buses, bikes, pedestrians, and rail. It can also model complex traffic control systems, such as adaptive signals and ramp metering. TransModeler is a mesoscopic model that can simulate large-scale networks with dynamic traffic assignment and routing. It can also model freight and commercial vehicles, as well as emergency vehicles and evacuations. AIMSUN is a hybrid model that can switch between macroscopic, mesoscopic, and microscopic modes depending on the level of detail required. It can also model traffic demand management strategies, such as congestion pricing and parking management. Lastly, CORSIM is a microscopic model that can simulate urban and freeway traffic, including signal coordination and queue spillback. It can also model traffic incidents and work zones.

4 How to apply traffic simulation models to evaluate land use changes?

When applying traffic simulation models to evaluate land use changes, it is necessary to follow a general process that involves four steps. First, you must define the objectives and scope of the analysis, including the land use scenarios to compare, the performance measures to evaluate, and the data sources and assumptions to use. Second, build and calibrate the base model by determining the network geometry and topology, estimating traffic demand and supply parameters, and validating and calibrating the model to match observed conditions. Third, develop and implement the land use scenarios by considering changes in land use density, mix, and location, as well as how these changes affect traffic generation, distribution, and assignment. Finally, run and analyze the model results by examining differences in traffic performance between the base and land use scenarios by time of day, location, and mode. It is also important to interpret and communicate the model results to stakeholders and decision-makers.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?