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OCR for page 72
72 APPENDIX D Suggested Revisions to MMUCC Guideline Definitions of a divided trafficway provided to enable vehicles to do Revisions to Existing Definitions a U-turn, or a work zone type with a connection between Activity Area--currently defined as "Located adjacent to the two roadways of a divided highway where vehicles are actual work area, whether workers and equipment were diverted from one roadway onto the other, such that both present or not." This definition is inconsistent with the directions of travel use a single roadway." definition in the MUTCD and with the Diagram in appen- Flagger--the current definition "Traffic control person con- dix L of the Guideline. This definition should be made trolling traffic with a flag applicable to the motor vehicle at consistent with the MUTCD by changing it to "the part of the crash location" is incomplete in that the required device the work zone where the work takes place. It includes the is now a stop-slow paddle, with a flag used for only limited traffic space, work space, and buffer spaces." situations. The definition should be revised to read "Traffic Advance Warning Area--currently defined as "Located after control person controlling traffic with a stop-slow paddle the first warning sign but before the work area." This defi- or flag applicable to the motor vehicle at the crash location." nition is also with the MUTCD and appendix L, and Helmet--the current definition "Safety helmet worn by non- should be revised to "From the first warning sign to the motorist (bicyclist) or driver (motorcyclist)" should be start of the transition area." expanded to read "Safety helmet worn by non-motorist Concrete Traffic Barrier--currently defined as "A type of (bicyclist) or driver (motorcyclist) or a protective hardhat permanent median made of concrete that is usually fixed worn by a worker." The term itself should be changed to but sometimes can be moved by special equipment to shift "Helmet or Hardhat." lane direction." This definition is inconsistent with high- Impact Attenuator/Crash Cushion--the current definition is way terminology, and is incorrect in that this feature is a "A barrier at a spot location, less than 25 ft. (7.6 m) away, traffic barrier, not a median. The suggested revised defini- designed to prevent an errant motor vehicle from impact- tion would read "a type of permanent traffic barrier made ing a fixed object/hazard by gradually decelerating the of concrete that is located in a highway median or on the motor vehicle to a safe stop or by redirecting the motor ve- roadside. Although usually fixed in place, some versions on hicle away from the hazard." This term should be revised this barrier can be quickly moved from side-to-side by a to "Impact Attenuator/Crash Cushion Permanent" and special machine to open and close lanes." It is suggested its definition changed to "A barrier permanently fixed at a that the term itself be revised to "Concrete Traffic Barrier-- spot location, less than 25 ft. (7.6 m) away, designed to pre- Permanent" to distinguish from the two new terms "tem- vent an errant motor vehicle from impacting a fixed porary work zone concrete barrier-non-moveable" and object/hazard by gradually decelerating the motor vehicle "temporary work zone concrete barrier-moveable" defined to a safe stop or by redirecting the motor vehicle away from below. the hazard." A new term for "Impact Attenuator/Crash Crossover--the current definition "Area where motor vehi- Cushion--Work Zone" is defined below. cles are permitted to travel across the opposing lanes of Intermittent or Moving Work--currently defined as "Type of traffic or do a U-turn" is potentially confusing, especially work zone." This definition is too brief, and in incomplete. in work zones, because it seems to include intersections. A suggested revised definition is "Type of work zone that The term crossover has a very specific meaning in WZs, moves intermittently or continuous along a highway, and and this term should be revised to read "Area in the median remains in one location for no more than a few minutes."

OCR for page 72
73 Lane Closure--the current definition "Type of work zone" of work zone in which the activity takes place on a shoul- should be expanded to read "Type of work zone in which der or median, but not in a travel lane, and no travel lanes one or more travel lanes are closed to traffic, with traffic are disrupted." moved into the remaining open lanes, thus resulting in a Work Zone/Maintenance Equipment--It was suggested in reduction in the total number of lanes available for travel." the discussion of attribute revisions that this term be revised Lane Shift/Crossover--the current definition of "Type of to include equipment and vehicles. Accordingly, the cur- work zone" is incomplete, and is inconsistent with the sug- rent definition "Equipment related to the work zone or gested revised definition for crossover provided above. It is roadway maintenance" should be revised to read "Equip- recommended that this term be shortened to "lane shift" ment or vehicles related to the work zone or roadway con- and that the definition be revised to "a traffic lane is moved struction, maintenance, or utility work." laterally in either direction, but the total number of lanes is not reduced. Suggested Additional Definitions Non-Highway Work--the existing definition "Maintenance or other types of work occurring near or in the trafficway but Activity area--the part of the work zone where the work not related to the trafficway" does not clearly explain what takes place. It includes the work space as well as the traffic should be included under this category. It appears it is in- space and any buffer spaces. tended to identify work on utility infrastructure such as Buffer Space--Area within the activity area provided for the overhead transmission lines. It could also include work on protection of traffic and workers by providing room for an property adjacent to a highway, such as building repair or errant vehicle to stop or to return to the traffic space. demolition, which requires closing or shifting a sidewalk, Impact Attenuator/Crash Cushion--Work Zone--A bar- shoulder, or even a travel lane. It is not clear whether an ex- rier temporarily placed at a spot location in a work zone, cavation or similar work within the roadway to install or less than 25 ft. (7.6 m) away, designed to prevent an errant repair an underground facility would be categorized as motor vehicle from impacting a fixed object/hazard by Non-Highway Work. A related major concern is that the gradually decelerating the motor vehicle to a safe stop or by law enforcement officer that enters this information may redirecting the motor vehicle away from the hazard." not be able to determine whether the activity necessitating Temporary Work Zone Concrete Barrier--Moveable-- a work zone is Highway Work or Non-Highway Work. This similar to Temporary Work Zone Concrete Barrier-- attribute is included in data element C15. "Contributing Non-Moveable, except it can be quickly moved from Circumstances, Road," but its purpose is unclear. It is rec- side-to-side by a special machine to open and close lanes. ommended that definition should be re-examined in the Temporary Work Zone Concrete Barrier--Non-Moveable-- planned next edition of the guideline. a type of traffic barrier made of concrete that is located in Stop Signs--the current definition reads "A six-sided red a highway median or roadside in a work zone. This barrier sign with "STOP" on it, requiring motor vehicles to come consists of individual sections that are set in place and to a full stop and look for on-coming traffic before pro- pinned together. This barrier can be relocated within the ceeding with caution." Stop signs are required by the work zone, and is removed at the completion of the work. MUTCD to include eight sides, and this definition should Traffic Space--the part of the activity area available for the be revised accordingly. use of traffic (vehicles, pedestrian, bicycles) to pass through Transition Area--the current definition "Where lanes are the activity area. shifted or tapered for lane closure" is incorrect in that the Work Space--the part of the activity area set aside for work- transition area includes any change in the normal traffic ers, equipment, and material storage. The work space is pattern, not just lane closures or shifts." It should be re- typically marked by traffic cones, drums or similar devices vised to read "That part of a work zone located prior to the or by the presence of work vehicles. Activity Area where traffic is moved out of its normal path, Work Space Intrusion--A vehicle traveling through a work such as at a lane closure, lane shift, lane width reduction or zone enters the work space and collides with a worker, median crossover." work zone/maintenance equipment or vehicle, or another Work on Shoulder or Median--the current definition "Type work zone feature such as an excavation of material of work zone" should be redefined for clarity to read "Type stockpile.