Overview of Highway Design

Question 1

a process in Highway Engineering where the
most appropriate location, alignment, and shape of a highway are
selected.

Answer 1

Highway design

Question 2

Five Major factors in Highway Design

Answer 2

*Human Factors and Driver Performance
* Vehicles
* Traffic Characteristics
* Physical Elements
* Economic Factors

Question 3

Some of the most common data needed for highway design are as follows:

Answer 3

• Field Survey Information (Topo)
• Alignment
• Spatial Data
• AADT (Annual Average Daily Traffic)
• Subsurface Investigations
• Catchment Areas (For Cross Drain Design)
• Existing Streams/Rivers
• Existing Structures and Utility Services

Question 4

a 3D representation of the project site

Answer 4

Topographic Surveys

Question 5

It is the route of the road, defined as a series of horizontal tangents and curves. it also called the horizontal control.

Answer 5

Alignment

Question 6

helps in better decision making when designing highways. GIS software is commonly used for identifying spatial data. QGIS is an example of a GIS software

Answer 6

Spatial data

Question 7

the total volume of vehicle traffic on a highway or road for a year divided by 365 days.

Answer 7

Annual average daily traffic (AADT)

Question 8

area of land that collects water after rainfall.
Water flows down into these areas and collects into rivers and streams.

Answer 8

Catchment Area

Question 9

Design Preocedure

Answer 9

1. Obtain topographic survey through any of the different methods
2. Plot the data in any road analysis software (Civil 3D, MX Road,
   OpenRoads) to model the surface
3. Plot the alignment
4. Adjust the alignment making sure all factors are put into
   consideration
5. Generate the existing profile
6. Create a design profile making sure that it passes all design criteria
   and standards
7. Create the cross section depending on the necessary features of
   the highway
8. Generate the corridor
9. Layout the drainage system
   10.If using a pipe network for storm drains, do Rainfall Analysis and
   Runoff Analysis in Storm and Sanitary Analysis (SSA)
   11.If using retaining walls and structures, use slope stability software
   like GEO5 for analysis
   12.Add traffic signs and markings as needed
   13.Iterate until optimum design is achieved

Question 10

The most efficient alignment is a __________?

Answer 10

Straight Line

Question 11

It is the target speed at which drivers are intended to travel
on a street, and not, as often misused, the maximum operating speed

Answer 11

Design speed

Question 12

the distance at which a driver of a vehicle can see an
object of specified height on the road ahead

Answer 12

Sight Distance

Question 13

the minimum distance required for a
vehicle, travelling at the design speed, to stop before reaching an
object in its path

Answer 13

Stopping Sight Distance

Question 14

the distance needed for a driver to
detect an unexpected threat, recognize the threat, decide on what to do and initiate a maneuver to avoid the said threat

Answer 14

Decision Sight Distance

Question 15

the minimum distance required to safely
make a normal passing maneuver on 2-lane highways

Answer 15

Passing Sight Distance