Office of Safety and Operations 

Research and Development 

1

Saxton Transportation Operations Laboratory Research Tools to 

Advance Cooperative Driving Automation (CDA) Research

The Federal Highway Administration’s (FHWA) CDA Program aims to enhance road infrastructure capabilities, 

improve vehicle safety and efficiency, and advance research on connectivity between infrastructure, automated 

vehicles, and other road users. These efforts help shape the future of transportation and foster the development of 

an integrated intelligent transportation system where automated vehicles, infrastructure, and other road users 

seamlessly work together.

Simulations help users to understand and explore various models of transportation systems and technology. The 

CDA simulation environment leverages multiple simulation frameworks, including the CDASim anything-in-the-loop 

cosimulation tool,(1) CARLA Simulator,(2) and Eclipse® SUMOTM,(3) to expand the capacity of CDA. The CDASim tool 

specifically supports the CARLA Simulator and Eclipse SUMO environments, both of which are open-source 

cosimulation tools available to the public.

CDASIM COSIMULATION TOOL

CDASim(1) establishes anything-in-the-loop capabilities for assessing CDA simulations, which involves constructing 

anything-in-the-loop capabilities through open-source software that is publicly accessible for customization to the 

customer’s CDA requirements. Anything-in-the-loop technology is based on the developed CDA simulation 

framework and contributes to building a comprehensive simulation environment that allows for further testing of 

automated driving systems and software, utilizing both vehicle and traffic simulators as illustrated in figure 1.

CDASim includes the following key benefits:

 Facilitates development, 

testing, and deployment of 

CDA algorithms and 

applications.(1)

 Enables users to conduct 

thorough testing of 

autonomous driving 

systems and technology 

within safe, controlled 

virtual environments before 

real-world implementation.

 Evaluates the performance 

of CDA algorithms and 

applications.

 Helps users adapt and use 

CARMA PlatformSM (4) to 

support their CDA research.

© Getty Images Plus.

Figure 1. Diagram. CDASim cosimulation tool components. 

(See references 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10.)

Source: FHWA.
TITLE OF TECHBRIEF

2

For more information, please contact the CDA Program at CDA@dot.gov

FHWA-HRT-24-034

HRSO-40/12-23(200)E

Recommended citation: Federal Highway Administration. Saxton Transportation Operations 

Laboratory Simulation Tools to Advance Cooperative Driving Automation (CDA) Research

(Washington, DC: 2023) https://doi.org/10.21949/1521459

RESEARCH TOOLS TO ADVANCE CAV RESEARCH

1. FHWA. n.d. “cdasim” (software and configuration files in GitHub repository). https://github.com/usdot-fhwa-stol/cdasim, last accessed 

April 12, 2023. 

2. CARLA Team. 2023. “CARLA” (web page). http://carla.org//, last accessed October 23, 2023.

3. Eclipse Foundation. n.d. “Simulation of Urban MObility” (web page). https://www.eclipse.dev/sumo/, last accessed October 23, 2023.

4. nsnam. 2021. ns-3 (software). Version 3.35. https://www.nsnam.org/, last accessed November 6, 2023.

5. AASHTO, ITE, and NEMA. 2019. National Transportation Communications for ITS Protocol Object Definitions for Actuated Signal Controllers (ASC) 

Interface. TCIP 2012 v03A. Washington, DC: American Association of State Highway and Transportation Officials (AASHTO); Washington, DC: 

Institute of Transportation Engineers (ITE); and Arlington, VA: National Electrical Manufacturers Association (NEMA). https://www.ntcip.org/

file/2019/07/NTCIP-1202v0328A.pdf, last accessed November 17, 2023.

6. Eclipse. 2021. MOSAIC (software). Version 21.1. https://www.eclipse.org/mosaic/, last accessed November 6, 2023.

7. FHWA. n.d. “carma-platform” (software and configuration files in GitHub repository). https://github.com/usdot-fhwa-stol/carma-platform, last 

accessed November 19, 2023.

8. Ghiasi, A., W. Goforth, D. Hale, Z. Huang, S. Racha, and S. Nallamothu. 2022. Cooperative Automation Research: High-Level Framework of CARMA 

Proof-of-Concept TSMO Use Case Testing for CARMA Streets. Report No. FHWA-HRT-21-107. Washington, DC: Federal Highway Administration.

9. FHWA. 2023. CARMA Cloud (software). Version 4.3.0.

10. FHWA. 2023. CARMA Messenger (software). Version 4.4.0.

CARLA SIMULATOR

The CARLA Simulator(2) facilitates the development, 

training, and validation of autonomous driving 

systems by providing software code, standardized 

protocols, and other digital resources tailored 

specifically for CARLA Simulator, all available to the 

public as open-source resources.

The CARLA Simulator includes the following 

key benefits:

 Enables comprehensive simulation of diverse 

traffic scenarios.

 Reduces costs linked to testing with physical 

vehicles and equipment.

 Accelerates development and deployment of 

autonomous driving systems.

ECLIPSE SUMO

Eclipse SUMO(3) is an open-source program that 

enables users to simulate large-scale traffic scenarios. 

This program encompasses various modes of 

transportation, including buses and passenger 

vehicles. Users can design diverse traffic scenarios 

and utilize tools with additional features including 

route finding, visualization, and emission calculations.

Eclipse SUMO includes the following key benefits:

 Provides realistic and detailed traffic simulations.

 Explores different vehicle types and traffic 

scenarios.

 Empowers users to customize the program to 

align with the requirements of their specific 

projects and interests.

 Offers visualization tools to enhance the user’s 

understanding of traffic patterns and scenarios.

GETTING STARTED

The tools discussed in the previous sections are available on GitHub, which enables collaboration and 

contribution that enhances users’ understanding and accelerates market readiness of CDA technologies.

GitHub provides a platform for users to collaborate, gain experience with CDA, and customize the software 

for their specific needs.

For technical support, please reach out to the CARMA Support Services Help Desk at 

CARMASupport@dot.gov. Additionally, a section of frequently asked questions is available on GitHub that 

offers solutions to commonly known issues.