2.0 Highway Development and Planning Flashcards
Functional classification groups highways by the character of service they provide, and is primarily based on motor vehicle travel characteristics and the degree of access to __________.
adjacent properties
The six recognizable stages in motor vehicle travel include main _______, _______, _______, _______, _______and _______. Each of these stages is handled by a separate facility designed specifically for its function.
movement, transition, distribution, collection, access and termination.
The traffic characteristic which has the greatest effect on highway design is the _______ of _______. The design element which is the most affected by the volume of traffic is the number of traffic lanes.
Volume of traffic
The design element which is the most affected by the volume of traffic is the _______of _______.
The number of traffic lanes
In modern practice, single-lane and 3-lane highways are considered _______ as parts of an improved highway system
Inappropriate
From the standpoint of engineering design and construction at least _______ lanes should be considered in any proposed highway no matter how low the traffic volume may be.
2-traffic lanes
_______ types are therefore considered to be 2-lane, multi-lane (four or more lanes), undivided and multilane divided highways.
Highway
Lane Width or Carriage way Width = 3.00 m to 3.65 m (Standard: ___m)
3.35 m
Shoulders = ___m wide
3.00 m wide
- Climbing Lane (For grade > 6%) = ___m to ___m wide
Note: If a hill is too steep and trucks going up make it even harder, it’s a good idea to add an extra lane for those climbing trucks. This is especially needed when the number of trucks going up is 20% or more than what the road can normally handle.
3.00 m to 3.35 m wide
The climbing lane should begin near the foot of the grade at a point determined by the speed of the trucks at the approach to the grade. Where practicable, the climbing lane should end at a point beyond the crest where the truck can attain a speed of ___kph.
50kph
What are the characteristics and considerations for the narrowest highways intended for one-way traffic lanes?
- These highways have traffic lanes intended for one-way use, with passing accomplished on lanes not subject to opposing traffic.
- The ability to pass without entering the lane of opposing traffic results in smoother operation and increased highway capacity.
- They typically have a speed limit of 60 kph or less and should feature prominent road markings to separate opposing traffic streams.
- Adequate shoulders are essential to encourage drivers to use them in emergencies.
- Undivided highways are most applicable in urban and suburban areas with concentrated development of adjacent land.
Highways with widely separated roadways have advantages like
easy vehicle operation, better drainage, and a nice look.
Open views between separated roadways help show that they’re meant for _______ on long divided highways.
one-way traffic
A divided highway has separated roadways for traffic in opposite directions. It usually has _______ per direction and a wide median for safety
two full lanes
Divided highways are safer, more comfortable, and good for _______, _______.
high-volume, high-speed traffic.
What is the recommended median width for rural areas?
Medians 1.20m to 1.80m wide are recommended for rural areas.
What is the ideal median width for separating traffic and planning intersections?
Wider medians, ideally 4.50m to 18.50m, are better for separating traffic and planning intersections.
_______ on multilane roads might be needed if long uphill stretches reduce capacity by 30% or more compared to normal traffic
Climbing lanes
How can super elevation runoff be managed when designing divided highways with medians?
by super elevating the entire road, including the median, as one section.
What happens to the median if it stays flat during the super elevation of a divided highway?
the pavements rotate around it during super elevation.
