TOTAL TERMS PT 5
level of service
An index of the operational performance of traffic on a given traffic lane, roadway, or intersection, based on service measures such as delay, degree of saturation, density and speed during a given flow period.
White
Background color for most signs and legends for some colored background.
Traffic Cones
Devices which may be conical in shape or tubular shaped capable of performing channelization of traffic which may be set on the surface of the roadway or rigidly attached for continued use
PIEV time
The time needed for a driver to recognize and respond to the cue is called
I. Be needed II. Command attention III. Convey a clear, simple message IV. Command respect V. Be placed to get the proper response from the driver
The traffic control device must:
Green
Used as background color for direction signs.
Roadwork Signs
Warn or advise of temporary hazardous conditions that could endanger road users or the men and equipment engaged on roadwork
Warning Signs
Warn road users of condition on or adjacent to the road that may be unexpected or hazardous
Flashing Lamps
Warning devices used to supplement other controls and devices necessary to alert motorists of construction and maintenance activities or obstructions in the roadway
Transverse pavement markings
include crosswalks, stoplines, turn movement restrictions, and parking spaces.
Barriers
Highway appurtenances designed to prevent vehicular penetration from the travel way to areas behind the barrier such as to minimize damage to impacting vehicles and their occupants, and to reduce the risk of injuries to pedestrians and workers
Traffic Control Devices
is a sign or pavement marking that is used to regulate, warn, or guide drivers as they operate their vehicles.
Perception
is the time it takes to see the sign. This is the time needed to locate the cue and classify the cue as a sign to be read.
Emotion
is the time to consider the sign's meaning and make a decision. Sometimes, the decision is that no action is needed. In other cases, the type of action must be decided.
Volition
is the time to react or execute a maneuver. A typical driving maneuver is to apply the brakes or turn the steering wheel.
Identification
is the time to read and understand the sign. The average driver comprehends three words per second.
Pavement Markings
like roadway signs, are used to warn, regulate, and inform motorists. Knowing what various pavement markings mean is important to the motorist, because they have the same force of law as signs.
[MAY 2022] Driving Task
Operating a motor vehicle on a street or highway can be complex and demanding at times, but it can be boring at other times. This range of circumstances - coupled with the range of driver capabilities - presents a challenge to the highway designer.
Brown
Reserved as background color for all tourist facility directional and information signs
I. Network Screening II. Diagnosis III. Select countermeasures IV. Economic Appraisal V. Prioritize Projects VI. Safety Effectiveness Evaluation
Road Safety Management Process:
Temporary Curbing
Roadwork devices consisting of pre-cast concrete sections, sandbag, and others which, may be used to guide traffic at the construction site
Overhead Signs
Signs which provide means of displaying essential traffic information on wide multi-lane roads, where some degree of lane use control is required, or where side-of-road clearance is insufficient to accommodate a roadside sign
Circle
Standard sign shape: Mainly used for regulatory signs;
Rectangle with long axis horizontal
Standard sign shape: Used for directional signs, service signs, road work signs, signs for special purposes, and supplementary plates for warning signs;
Octagon
Standard sign shape: Reserved exclusively for the STOP sign
Equilateral triangle, one point vertically downward
Standard sign shape: Reserved for the GIVE WAY sign;
Perception-Reaction Times
A driver sees most cues (signs, potential threats) soon enough to process them safely by routine driving actions - reduce speed, change vehicle path, or simply monitor the situation
Used as background color for service signs.
Blue
All of the above
Classification of Signs I. Regulatory Signs II. Warning Signs III. Guide Signs or Informative Sign IV. Signs for Expressways V. Signs for Special Purposes VI. Hazard Makers
I, II
Components of stopping sight distance I. Road Geometry II. Reaction Distance III. Braking Distance IV. Driver V. Vehicle
Traffic Signs
Device mounted on a fixed support (permanent signs) or portable support (temporary signs) whereby a specific message is conveyed by means of words or symbols placed or erected for the purpose of regulating, warning, or guiding traffic
ergonomics or engineering psychology
Human Factors, also called _____ , is the study of how human beings function in their natural or constructed surroundings.
I. Regulatory: rectangle; black on white or red II. Warning: diamond; black on yellow III. School Zone: Schoolhouse shape; black on fluorescent yellow-green IV. Work Zone: Diamond; black on orange V. Recreational and Cultural interest: rectangle or trapezoid; white on brown
In general, traffic signs can also be categorized by shape and color:
Guide Signs
Inform and advise road users of directions, distances, routes, the location of services for road users, and point of interest
1. Navigation (Route Selection) - Because most trips are made repeatedly, or in familiar street networks, this is usually the least complex of the driving task elements. However, when a driver is looking for information to reach a destination in an unfamiliar network, that activity may detract from other driving task elements. 2. Guidance (Vehicle Tracking) - Staying on the roadway and staying in the proper lane have obvious implications for safety. Examples: Lane and edge markings on the pavement, and delineators along the roadside. 3. Control (Object Avoidance) - This activity involves proper application of steering and speed control skills. At the basic level, steering around clearly visible fixed objects and maintain a safe distance from vehicles ahead and to the side constitutes the control element.
It is helpful to begin by considering the three essential elements of the driving task:
1. to indicate that the vehicle is registered 2. to uniquely identify the vehicle for law enforcement, data collection, or toll collection purposes.
License plate design and law enforcement - the license plate on a motor vehicle serves two principal functions:
Railroad grade crossings
More than half of such deaths are attributable to motor vehicle operator inattention or impatience. Motorists fail to see the train, misjudge its speed, or simply lose a race to the tracks. Many of these fatal collisions occur at crossings with active warning devices.
Changing the status quo
Normally, expectancy is a design feature that helps motorists. A straight road will stay straight until a sign that warns of a curve ahead appears. Traffic signals are usually placed above the intersection, on cables or on masts.
flow
Number of vehicles or pedestrians per unit time passing (arriving or departing) a given reference point.
All of the above
Shoulder paving is a valuable method of providing: I. Integrity of the pavement II. Width to place edge line pavement markings III. Additional safety to prevent vehicles skidding or drivers losing control in gravel IV. Low maintenance costs compared with unpaved shoulders
Regulatory Signs
Signs that inform road users of traffic laws and regulations, which if disregarded, will constitute an offense
Special Instruction Signs
Signs that instruct road users to meet certain traffic rule requirements or road condition
Delay
The additional travel time experienced by a vehicle or pedestrian with reference to a base travel time
Capacity
The maximum sustainable flow rate at which vehicles or persons reasonably can be expected to traverse a point or uniform segment of a lane or roadway during a specified time under given roadway, geometric, traffic, environmental, and control conditions; usually expressed as vehicles per hour, passenger cars per hour, or persons per hour.
density
The number of vehicles per unit distance along a road segment as measured at an instant in time.
I, II, III
The provision of safety sight distance depends on the following: I. Driver II. Vehicle III. Road Environment IV. Time of Day
I. White Markings, such as lane lines, separate traffic going in the same direction on multi-lane or one-way roads II. Dashed (or broken) lines separate lanes of travel where changing lanes is not restricted and where the lane use is not restricted. III. Solid white lines are restrictive
White Lines
I. Yellow Markings such as centerlines separate traffic flow going in opposite directions. II. Dashed (or broken) yellow lines on the motorist's side indicate where passing is permitted on two-lane two-way roads. III. Solid yellow lines indicate where passing is not permitted, although turning into a driveway across them is allowed where not prohibited. IV. A single yellow line indicates the left edge of a divided roadway.
Yellow Markings
Traffic signs
are placed into three major classifications, defined by their function - Regulatory, Warning, and Guide Signs.
Delineators
are used to guide drivers through turns, especially at night or at times of poor visibility.
Object markers
are used to obstructions within or adjacent to the roadway