Lexington Area ITS Architecture

Roadway Variable Speed Limits Functional Area

Description

'Roadway Variable Speed Limits' includes the field equipment, physical overhead lane signs and associated control electronics that are used to manage and control variable speed limits systems. This equipment monitors traffic and environmental conditions along the roadway. The system can be centrally monitored and controlled by a Traffic Management Center or it can be autonomous, calculating and setting suitable speed limits, usually by lane. This application displays the speed limits and additional information such as basic safety rules and current traffic information to drivers.

Included In

LFUCG Variable Speed Limit Signs

Functional Requirements

ID	Requirement
01	The field element shall monitor traffic and environmental conditions along the roadway.
02	The field element shall autonomously calculate and set variable speed limits based on current conditions by lane.
03	The field element shall receive commands from the controlling center that establish speed limits by lane.
04	The field element shall display the current speed limits per lane to drivers.
05	The field element shall display additional information such as basic safety rules and current traffic information to drivers.
06	The field element shall collect operational status of the variable speed limit field equipment and report the operational status to the controlling center.
07	The field element shall monitor and report faults to the controlling center.
08	As part of speed harmonization, the field element shall display suggested speed per lane to drivers.
09	As part of speed harmonization, the field element shall send suggested speed per lane to the RSE for transmittal to connected vehicles