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MUTCD. KEY Concepts for Traffic Control Applications. Distinguishing Terms. Standard - is required or specifically prohibited - interpret as “Shall” Guiidance - a statement of recommended practice in typical situations - interpret as “should”
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MUTCD KEY Concepts for Traffic Control Applications
Distinguishing Terms • Standard - is required or specifically prohibited - interpret as “Shall” • Guiidance - a statement of recommended practice in typical situations - interpret as “should” • Options - permissive with no requirements – interpret as “may”
Authority for MUTCD • Code of Federal Regulations (CFR) Part 655, Subpart F • Part 23 of the US Code, specifically 109 d and 402(a) refer to the authority of the FHWA
Elements included in the Authority • Design of the Control Devices (Color, shape, size, lettering, symbols, etc) • Placement and Operation ( typically identified as “Guidance” ) • Maintenance – to provide clean, legible messages that maintain respect
MUTCD Standards related to use of Control Devices • 1) All regulatory traffic control devices Shall be supported by laws, ordinances or regulations; but • 2) shall not be a legal requirement for their installation. Decisions to use devices are to be based on engineering studies and judgment.
Legal implications • Recall statement 2 when we discuss liability issues later. Agency’s aren’t required to install particular devices, but if they do they have a continuing responsibility to maintain the devices to meet accepted practice. Control devices SHALL be displayed only for the specific purposes as identified in the MUTCD
Associated documents • Standard Highway Signs • Standard Alphabets for Highway Signs and Pavement Markings • Standard Color Tolerance Limits • ( Consideration for elderly drivers addresses issues associated with the above documents)
Example recommendation for larger lettering on Work Zone Sign • RIGHT LANE CLOSED • Minimum visibility distance to take action is 330 feet at 55mph or 370 feet at 65 mph • Sample of Road User results: Best observers could see at 650 feet Poorest observers at 140 feet Sample tended towards the lower end of the range.
Example recommendation for larger lettering on Work Zone Sign • RIGHT LANE CLOSED • Minimum visibility distance to take action is 330 feet at 55mph or 370 feet at 65 mph • Sample of Road User results: Best observers could see at 650 feet Poorest observers at 140 feet Sample tended towards the lower end of the range.
Visibility Considerations - COLOR See Page 247 – Table 43 of Highway Design Handbook for Older Drivers and Pedestrians Daytime and Night time visibility for Construction Zone Orange Colors
Example 2 – Flourescent sheeting • Midday observation – facing north From 120 meters 93% detected flourescent orange signs 43% detected standard orange signs Flourescent orange costs $2.00 more per sign. (from report on research) – Can we justify it?
Another strategy CONSTRUCTION ZONE AHEAD WORK ZONE AHEAD
How does this affect your senses? • the olny iprmoetnt tihng is taht the frist and lsat ltteer be at the rghit pclae.