CE421: Short Quiz 1 (Road Signs, Signals, and Symbols)
1. Excessive delay to motorists and pedestrians 2. Disobedience to signal indications and other particular installations 3. Diversion of traffic to less advantangeous and undesirable routes 4. Increased accident frequency like rear-end collisions and pedestrians
4 Effects of Too Much Use of Traffic Symbols
1. To lead to a safe road traffic 2. To facilitate the traffic 3. To indicate traffic rules 4. To inform the drivers how to use the highway
4 Objectives of Road Traffic Signs
1. Simultaneous coordination 2. Alternative Coordination 3. Limited Progressive system 4. Flexible Progressive System
4 Systems of Coordination
1. Uniformity 2. Homogeneity 3. Simplicity 4. Valorization Principle 5. Concentration Principle 6. Legibility Principle
6 Basic Principles of Road Signs
1. Provide orderly movements of traffic 2. Increase the traffic handling capacity of intersections 3. Reduce the frequency of certain types of accidents 4. Coordinate traffic under conditions of favourable signal spacing so that it flows continuously at definite speed 5. Interrupt heavy traffic to permit crossings by other vehicles or pedestrians 6. Control the traffic lane use 7. Provide ramp control at freeway entrances 8. interrupt traffic for emergency vehicles and at movable bridges
8 Functions of Traffic Signals
1. Danger/Warning Signs 2. Intersection Signs 3. Prescription Signs 4. General Information Signs 5. Direction Signs 6. Agglomeration Signs 7. Railway Crossing Signs 8. Temporary Signs 9. Special Instruction Signs
9 Categories of Road Signs
End of Prescription Signs
A category under prescription signs which are circular in shape and represents the same bar sign obligation symbol. a red bar from right top to eleft bottom cancels this obligation
Obligation Signs
A category under prescription signs which are circular in shape with a dark blue background, wherein the symbols and border is white
Prohibitive signs
A category under prescription signs which have a white background, red ring, and prohibitive red bar, symbols, and letters
Pre-timed Signals
A classification of traffic signal where the traffic time intervals are divided to the various traffic movements
Traffic Activated Signals
A classification of traffic signal where time intervals are controlled as a whole or in part by traffic demands
Identification
A parameter of visibility and legibility refering to the analysis of the form and color of road signs
Reading
A parameter of visibility and legibility refering to the fundamental role of road signs
Detection
A parameter of visibility and legibility where the minimum area in contrast with the environment perceptibility by human eye
intersection Signs
A road sign category that lets drivers know what lies ahead
Warning/Danger Signs
A road sign category used to warn traffic of potentially hazardous conditions on or adjacent to the roadway
Informative Sign
A road sign category which are square in shape with a dark blue bcakground, white symbols and letters bounded by white borderline
Informative Sign
A road sign category which gives the driver miscellaneous information useful in his driving and general knowledge
Prescription Signs
A road sign category which informs the drivers of the traffic laws and regulations that could be an offense to anyone who disregard and violate it
Homogeneity
A road sign principle where in given the same conditions, the user notices signs or markings with the same value and importance
Legibility Principe
A road sign principle where indications or analogical messages should be reduced and road signs should be properly distributed
Concentration Principle
A road sign principle where it is necessary that some road signs must be seen at the same time, and should be installed for the driver to see at a glance by night and day
Simplicity
A road sign principle which avoids superabundance of signs that overstrain the drivers
Valorization Principle
A road sign principle which means to use only the needed and useful signs
Uniformity
A road sign principle which prohibits to use unofficial signs and markings
Flexible progressive system
A system of coordination provided with a master control that commands the controller for the individual signals
Alternative coordination
A system of coordination where in all signals changes their indication at the same time, but adjacent signals along the streets show different colors
Simultaneous coordination
A system of coordination which makes all color indications along the street alike at the same time
Limited Progressive System
A system of coordination which retains a common cycle length providing separate GO at each intersection to motor traffic progression
Traffic signal
All power operated traffic control devices, except flashers, signs, and markings for directing or warning motorists, cyclists, or pedestrians
1. Advance Direction sign 2. Intersection Direction Sign 3. Reassurance of Confirmatory Sign 4. Entering and Exit out of Urban Area
Direction signs are divided into 4 Categories.
Variable
Fill in the blanks: On urban areas, the distance between the successive intersections is __________________ including the warning signs.
Intersection and preceeding junction
Fill in the blanks: Road signs are located between the _____________________ and the _____________________________ on urban areas.
To attract driver's attention in areas of dangerous points linked to: 1. The highway structure such as curves, humps, dips, and narrowing 2. Conditions of the road such as slippery, falling rocks, and the like. 3. Other transport infrastructures like opening bridge, airport vicinity, etc. 4. The condition of vehicles and pedestrian traffic, pedestrian crossing, children area 5. Local circumstances such as factory exit and quarry exit
Give the 5 Objectives of Warning Signs
Means arterial stop sign
Meaning of traffic signal color: flash red
Means proceed with caution
Meaning of traffic signal color: flashing yellow
Go to such direction
Meaning of traffic signal color: green arrow
Stop and wait for a green indication
Meaning of traffic signal color: solid red light
Go
Meaning of traffic signal color: steady circular green
450 meters ahead of the hazards
Placement of signs: On high-speed roads, how many meters should warning signs be posted ahead of the hazards?
1.80 - 3.6 meters from the pavement edge and the bottom should be 1.5 or more above the roadway
Placement of signs: how many meters should warning, regulatory, and advisory signs for rural roads should be mounted? How many meters should it be above the roadway?
75 meters away
Placement of signs: howmany meters away from the hazard should a warning sign be placed in an urban road?
250 meters away
Placement of signs: howmany meters away from the hazard should a warning sign be placed in rural road?
60 cm
Placement of signs: what is the horizontal clearance in cm between the curb face near the edge of the sign (with a 2.1 meters of minimum height above the curb when vehicles may park along the curb)?
Must be pressure sensitive
Reflective sheet for manual application
Must be tack free heat activated
Reflective sheet for mechanical vacuum heat application
Visibility and Legibility
Road signs and signaling must be visible and readable considering human eye limit that is not adaptable at night driving
In aluminum sheeting of at least 3 mm in thickness
Sign panels for warning, regulatory, and informative signs are manufactured in what kind of material and in what size?
150 meters
The normal distance between the intersections and the warning signs on rural areas
Spherical lens elements embedded in transparent plastic having smooth, flat surface
The reflective sheet used for road signs consist of what kind of elements and characteristics?
Road Signs
They tell you what the rules are and what the road conditions are like
1. Prohibitive signs 2. Obligation Signs 3. End of Prescription Signs
Three categories of Prescription Signs
Road Signs
Warns people of possible dangers and provide information
1. Pre-timed signals 2. Traffic Activated
2 Classifications of Traffic Signals
1. Detection 2. identification 3. Reading
3 Parameters of Visibility and Legibiility