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Friday, April 17, 2026, 6:44 AM
Site: Work Zone Safety Training
Course: Work Zone Safety Training (HOME)
Glossary: WZSC Glossary
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Object Marker

A device used to mark obstructions within or adjacent to the roadway.

Occupancy Requirement

Any restriction that regulates the use of a facility or one or more lanes of a facility for any period of the day based on a specified number of persons in a vehicle. MUTCD 2009 Edition with May 2012 Revisions 1 and 2

Occupant

A person driving or riding in a car, truck, bus, or other vehicle. MUTCD 2009 Edition with May 2012 Revisions 1 and 2

Open-Road ETC Lane

A non-attended lane that is designed to allow toll payments to be electronically collected from vehicles traveling at normal highway speeds. Open-Road ETC lanes are typically physically separated from the toll plaza, often following the alignment of the mainline lanes, with toll plaza lanes for cash toll payments being on a different alignment after diverging from the mainline lanes or a subset thereof. MUTCD 2009 Edition with May 2012 Revisions 1 and 2

Open-Road Tolling

A system designed to allow electronic toll collection (ETC) from vehicles traveling at normal highway speeds. Open-Road Tolling might be used on toll roads or toll facilities in conjunction with toll plazas. Open-Road Tolling is also typically used on managed lanes and on toll facilities that only accept payment by ETC. MUTCD 2009 Edition with May 2012 Revisions 1 and 2

Open-Road Tolling Point

The location along an Open-Road ETC lane at which roadside or overhead detection and receiving equipment are placed and vehicles are electronically assessed a toll. MUTCD 2009 Edition with May 2012 Revisions 1 and 2

Operating Speed

The speeds at which vehicles are observed operating during free flow conditions. Free flow speeds are those observed from vehicles whose operations are unimpeded by traffic control devices (e.g., traffic signals) or by other vehicles in the traffic stream. The 85th percentile of the distribution of observed speeds is the most frequently used measure of the operating speed. MUTCD 2009 Edition with May 2012 Revisions 1 and 2

Opposing Traffic

Vehicles that are traveling in the opposite direction. At an intersection, vehicles entering from an approach that is approximately straight ahead would be considered to be opposing traffic, but vehicles entering from approaches on the left or right would not be considered to be opposing traffic. MUTCD 2009 Edition with May 2012 Revisions 1 and 2

ORT

open-road tolling MUTCD 2009 Edition with May 2012 Revisions 1 and 2

Overhead Sign

A sign that is placed such that a portion or the entirety of the sign or its support is directly above the roadway or shoulder such that vehicles travel below it. Typical installations include signs placed on cantilever arms that extend over the roadway or shoulder, on sign support structures that span the entire width of the pavement, on mast arms or span wires that also support traffic control signals, and on highway bridges that cross over the roadway. MUTCD 2009 Edition with May 2012 Revisions 1 and 2