Performing environmental impact assessments

To perform environmental impact assessments, you may need vehicle emission data. Using Vissim, you have the following options to calculate the exhaust emission of vehicles.

Simplified method via node evaluation

Node evaluation also determines exhaust emissions (Evaluating nodes). The basis for these are formed by standard formulas for consumption values of vehicles from TRANSYT 7-F, a program for optimizing signal times, as well as data on emissions of the Oak Ridge National Laboratory of the U.S. Department of energy. The data refers to a typical North American vehicle fleet and does not differentiate between individual vehicle types. This allows you to use node evaluation for a more simple comparison of the emissions produced during different scenarios.

Precise method with EnViVer Pro or EnViVer Enterprise

EnViVer Pro is a program used to calculate exhaust emissions based on detailed vehicle record data from Vissim. Using this add-on module, you can determine the exhaust emissions for individual vehicle types.

The statistical emissions model in EnViVer Pro and EnViVer Enterprise calculates realistic values for CO2, NOx and PM10 emissions of different vehicle categories. The calculated emissions are based on speed-time profiles of vehicles. The emission models are updated annually and are kept for future calculations. With the update, new emission models are added and existing models, if available, are updated. EnViVer Pro and EnViVer Enterprise thus provide both current and previous emission models, which allow you to easily compare or recalculate values (Overview of add-on modules). For questions regarding the purchase of EnViVer Pro and EnViVer Enterprise for Vissim, please contact PTV GROUP under the following e-mail address: traffic.info@ptvgroup.com. For information on the products, please refer to the website of the provider TNO (www.tno.nl).

The COM interface or API approach with EmissionModel.dll

This approach requires programming knowledge, as you must create the EmissionModel.dll file or write your own scripts for using the COM interface. It allows you to use your own calculation algorithms and simulation data as input.

EmissionModel.dll

For the calculation of emissions, you can access the file EmissionModel.dll (Accessing EmissionModel.dll for the calculation of emissions). You must provide the EmissionModel.dll. It is not part of Vissim. The following data is transferred via the interface for all vehicles and each simulation time step:

• Accelerations
• Speeds
• Weights
• ID numbers
• Vehicle types
• Gradients

COM interface

To calculate emissions, you can create your own scripts and/or integrate your own applications into Vissim. Using the COM interface, for each time step, you can access all Vissim attributes, e.g. position, speed and acceleration of the vehicles (Using the COM Interface).

Noise calculation

Noise calculations are carried out using specialized external software, e.g. CADNA or SoundPLAN. Vissim can provide specific input data for these programs. Alternatively, you can use the COM port, write your own script or embed your own application into Vissim for noise emission calculation (Using the COM Interface).

Calculation of ambient pollution

Concentration values determine the impact of environmental interference factors affecting human health and the natural environment. Concentration values are not calculated in Vissim, but in external software programs that specialize in concentration value calculation. Vissim can provide specific input data for these programs.