Ohio DOT Variable Speed Limit Signs
Status
Existing
Description
Variable Speed Limit (VSL) signs are a planned ITS element related to Ohio's Active Traffic and Demand Management (ATDM) program that aims to increase travel time reliability on Ohio DOT roadways in major metro areas. VSL signs in the field would communicate centrally with the Ohio Statewide TMC, and reduced speeds would be implemented either by TMC operators or would be automated based on the level of traffic detected by nearby Ohio DOT Vehicle Detection Devices.
Stakeholders
| Stakeholder | Role | Role Status |
|---|
| ODOT | Owns | Existing |
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| ODOT | Owns | Planned |
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Physical Objects
Functional Objects
| Functional Object | Description | User Defined |
|---|
| Roadway Basic Surveillance | 'Roadway Basic Surveillance' monitors traffic conditions using fixed equipment such as loop detectors and CCTV cameras. | False |
|---|
| Roadway Environmental Monitoring | 'Roadway Environmental Monitoring' measures environmental conditions and communicates the collected information back to a center where it can be monitored and analyzed or to other field devices to support communications to vehicles. A broad array of general weather and road surface information may be collected. Weather conditions that may be measured include temperature, wind, humidity, precipitation, and visibility. Surface and sub–surface sensors can measure road surface temperature, moisture, icing, salinity, and other measures. | False |
|---|
| Roadway Time Management | 'Roadway Time Management' provides foundational time keeping functionality that supports an accurate, synchronized time reference in ITS field equipment. It receives accurate time information from an external source and maintains a local time reference using an internal clock in between time synchronizations. | False |
|---|
| Roadway Traffic Information Dissemination | 'Roadway Traffic Information Dissemination' includes field elements that provide information to drivers, including dynamic message signs and highway advisory radios. | False |
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| Roadway Variable Speed Limits | '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. | False |
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Physical Standards
| SDO | Document # | Title | User Defined |
|---|
| ITE | ITE ITS Cabinet | ITS Standard Specification for Roadside Cabinets | False |
|---|
| NEMA | NEMA TS 4 | Hardware Standards for Dynamic Message Signs (DMS) with NTCIP Requirements | False |
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| NEMA TS 8 | Cyber and Physical Security for Intelligent Transportation Systems (ITS) | False |
Interfaces To
(View Context Diagram)