USLIMITS2

*** To use the older USLIMITS system click here: USLIMITS

Would you like to use an expert system to help determine the most appropriate speed limit for a given route in your area? If so, click here to subscribe to the USLIMITS2 web application.

Already signed up? Please log in here.

USLIMITS2 Documentation (PDF)

This is an expert system (called USLIMIT2) for recommending speed limits in speed zones developed as part of NCHRP Project 3-67. The decision rules for this expert system were developed based on input from a panel of experts in this country.

This is the second generation of the USLIMITS application. The first generation of the USLIMITS application was developed by FHWA through help from the Australian Road Research Board.

The intent of this expert system is to help practitioners analyze specific segments of all types of roads from rural local roads to urban freeways

Statutory limits that apply to a category of roads within a jurisdiction are not included. Part time and temporary speed limits (e.g., school zones, work zones) are outside the scope of this product. In addition, this program does not provide maximum safe speed warnings for adverse alignments.

Before using the program, we suggest that you download and review the User Guide. The User Guide is available after you log-in.

The logic flow and the decision rules are described in the form of flow charts in the Decision Rules document. The Study Report describing the work in NCHRP Project 3-67 is also available for your information (the study report is a large document and may take significant time to download depending on the Internet connection that you have).

If you have any technical difficulties while using this program, or find any bugs, please send an email to help@uslimits.org