CE412 Group 3 – Flashcards

CE412 - Transportation Engineering - CE3L - Group 3

Pentagon

Problem 1.561: The geometric shape of School Crossing signs.

Pennant with longer dimension horizontal

Problem 1.562: The geometric shape of No Passing Zone warning signs.

Trapezoid

Problem 1.563: The geometric shape of the recreational use of guide signs.

Octagon

Problem 1.564: The geometric shape of Stop sign.

Equilateral triangle with one point down

Problem 1.565: The geometric shape of Yield sign.

Circle

Problem 1.566: The geometric shape used for the Railroad Crossing Advance warning sign and the Civil Defense Evacuation Route Marker.

Alligator cracking

Problem 1.567: A series of interconnected or interlaced cracks caused by fatigue failure of the asphalt concrete surface under repeated traffic loading.

Block cracking

Problem 1.568: Cracks forming large interconnected polygons, usually with sharp corners or angle. These cracks are generally caused by hardening and shrinkage of the asphalt and or reflection cracking from underlying layers such as cement-treated base.

Transverse cracking

Problem 1.569: Cracks approximately at right angles to the pavement centerline. These may be caused by shrinkage or differential thermal stress of the asphalt concrete or maybe reflective cracks.

Longitudinal cracking

Problem 1.570: Cracks approximately parallel to the pavement centerline. These are caused by poorly constructed construction joints and shrinkage of asphalt concrete surface.

Raveling

Problem 1.571: Wearing away of the pavement surface caused by the dislodging of aggregated particles and binder. This is usually a result of insufficient asphalt binder in the mix or stripping of asphalt from particles of aggregate.

Drip track raveling

Problem 1.572: Progressive disintegration of the surface between the wheel paths caused by dripping of gasoline or oil from vehicles.

Bleeding or flushing

Problem 1.573: The exuding of bitumen onto the pavement surface, causing a reduction in skid resistance. It is generally caused by excessive amounts of asphalt in the mix or low air voids content. It occurs when asphalt fills the void in the mix during hot weather and then exudes out onto the surface of the pavement.

Faulting

Problem 1.574: Elevation differences between adjacent slabs at transverse joints. It is usually the result of pumping and is a major source of Portland concrete pavement failure.

Blowups

Problem 1.575: Localized upward buckling and shattering of the slabs at transverse joints or cracks. They can occur when transverse joints are filled with incompressible solid materials.

Joint spalling

Problem 1.576: The breakdown or disintegration of slab edges at joints or cracks, usually resulting in the loss of sound concrete and the progressive widening of the joint or crack.

Surface attrition

Problem 1.577: Abnormal surface wear, usually resulting from poor quality surface mortar or coarse aggregate.

Surface polish

Problem 1.578: Loss of the original texture due to the traffic action.

Density

Problem 2.1: It is defined as the number of vehicles per unit distance occupying a section of roadway at a given instant time and is usually measured in vehicles per mile or per km.

Traffic volume

Problem 2.2: The number of vehicles moving in a specified direction on a given lane or roadway that pass a given point during specified unit time and is usually expressed as vehicles per hour or vehicles per day.

Traffic capacity

Problem 2.3: The ability of a roadway to accommodate traffic volume is expressed in units of maximum number of vehicles in a lane or a road that can pass a given point during a specified unit hour, that is vehicles per hour per lane or roadway.

Basic capacity

Problem 2.4: The maximum number of passenger cars that can pass a given point on a lane or roadway during one hour under the most nearly ideal roadway and traffic condition which can possibly be attained.

Possible capacity

Problem 2.5: The maximum number of passenger cars that can pass a given point on a lane or roadway during one hour under prevailing roadway and traffic conditions.

Practical capacity

Problem 2.6: The maximum number of vehicles that can pass a given point on a lane or roadway during one hour under the prevailing roadway and traffic conditions, when traffic is subjected to some degree of restrictions due to driver behavior or restrictions to the driver's freedom to maneuver under the prevailing roadway and traffic conditions.

Weaving

Problem 2.7: The crossing of two or more traffic streams traveling in the same general direction along a significant path of highway without the aid of traffic signals.

Spot speed

Problem 2.8: The instantaneous speed of a vehicle at a specified section or location.

Average speed

Problem 2.9: The average of the spot speeds of all vehicles passing a given point in the highway.

Space-mean speed

Problem 2.10: The average speed of vehicles in a certain road length at any time.

Time-mean speed

Problem 2.11: The speed distribution of vehicles at a point on the roadway and it is the average of instantaneous speeds of observed vehicles at the spot.

Running speed

Problem 2.12: The average speed maintained by a vehicle over a particular stretched of road, while the vehicle is in motion. This is obtained by dividing the distance covered by the time during which the vehicle is in motion.

Time headway

Problem 2.13: The time interval between the passage of successive vehicles moving in the same lane and measured from head to head as they pass a point on the road.

space-headway

Problem 2.14: The distance between successive vehicles moving in the same lane measured from head to head at any instance.

passing sight distance

Problem 2.15: The distance ahead that must be clear to permit safe passing is called:

skid resistance/coefficient of friction/coefficient of adhesion and hysteresis

Problem 2.16: The ratio between parallel forces divided by the normal forces is known as:

Expressway

Problem 2.17: Divided arterial highway for through traffic with full or partial control of access and generally with grade separations at major intersections.

Freeway

Problem 2.18: An expressway with full control of access.

Parkway

Problem 2.19: An arterial highway for non-commercial traffic with full or partial control of access and usually located within a park.

stopping sight distance

Problem 2.20: Minimum sight distance required for a driver to stop a vehicle after seeing an object in the vehicle’s path without hitting that object. This distance is the sum of the distance traveled during perception-reaction time and the distance traveled during braking.

overtaking sight distance

Problem 2.21: Minimum sight distance required on a two-lane, two-way highway that will permit a driver to complete a passing maneuver without colliding with an opposing vehicle and without cutting off the passed vehicle.

Super elevation run off

Problem 2.22: The length of super elevation development from zero cross slope to full design super elevation in a circular curve alignment.

Tangent run out

Problem 2.23: The length of super elevation development from the normal cross slope to the zero cross slope point on the tangent.

Provide a proportion of super elevation run off. This proportion tends to minimize the adverse effects of lateral acceleration and improves the safety of the transition from tangent to circular curve.

Problem 2.24: The location of super elevation development onto circular curves has been continuous throughout the world. This concern is due to the fact that high design super elevation is not available for the curve radius at the P.C. This results in the vehicle experiencing 2 to 3 sec. where lateral acceleration tends to force the driver to adopt a natural spiral curve during entry and exit. This problem can be prevented by:

Vertical alignment

Problem 2.25: The longitudinal profile along the centerline of the road. It is made up of a series of grades and vertical curves.