Concept & Significance of Highway Planning

 

Roads & Highways play a vital role in a country & for human society by providing mobility and connectivity. For the purpose of efficiency and efficient allocation of limited resources, planning is inevitable.Planning is determining in advance what is to be done and when is to be done, and who is to do it. It encompasses setting objectives as well as making day to day decision on how the objectives can be achieved. Highway should be planned according to volume of traffic by conducting adequate surveys. Highways should be constructed with minimum cost but should be safe and secured. Planning should be made by forecasting traffic for several years and should consider for maintenance, renewal and widening as well. Highway planning requires extensive studies & data collection in following fields:

a. Economic studies

1. Details of existing facilities & their utility

2. Distribution of population in an area

3. Production of agricultural & industrial sector and their future growth

4. Possibility of tourism

5. Change in land use and future trends of development

6. Per capita income

b. Traffic studies

1. Traffic volume per day, ADT (Annual daily traffic), AADT (Average Annual Daily Traffic)

2. Traffic flow patterns

3. Classes of traffic such as passenger cars, busses, trucks.

4. Axle loads

5. Anticipated future trends of traffic growth

c. Engineering studies

1. Study of topography

2. Soil investigation

3. Hydrology, geology

4. Ground water table

5. Problems related to construction, drainage and maintenance

d. Financial studies

1. Sources of funding

2. Estimated revenue from tolls, taxes

3. Yearly budget, monthly break down

4. Cost estimated

5. Mode of payment

6. Office setup

7. Human resources required to execute plan

Following factors needs to be considered for selection of highway alignment (Ideal alignment)

1. Directness- Routes should be direct as far as possible

2. Ease of construction, maintenance & operation

3. Safety

4. Economy

5. Special consideration

Factors controlling highway alignment

1. Obligatory points: For maximum utilization of routes

2. Topographical features: Bends, curves, tunnels, via-ducts

3. Geometrical design aspects: Radius of curve, longitudinal gradient, sight distance, road                             intersection, geometric design, design speed, lateral friction, super-elevation.

4. Cross drainage needs: Alignment should be such that bridge are at right angle to the flow of river.

5. Deviation according to circumstances

6. Availability to material & labor

7. Economic consideration

8. Political consideration

Significance of highway planning are

a. To enable highway to be safe, efficient, economic and comfortable.

b. To optimize the available resources and gain value for money

c. To evaluate the risks associated with construction and management of risk.

d. To construct highway in specified time with desired quality

e. To make highway sustainable by assessment of future needs.

f. To work out financing system

g. To identify periodic maintenance, regular maintenance, rehabilitation schedule.

h. To set the alignment of highway and fix geometric design.

i. To identify the required pavement design for highway.

For rational use and efficient use of resources, planning is necessary. Certain objectives and goals should be fixed during planning. In addition to this, each & every future actions and outputs should be forecasted and in advance solution should be identified for the problems. The targets and objectives should be SMART (Specific, Measurable, Achievable, Reasonable and Time bounded). Allocation of resources and ascertaining of human resources should be done during this phase. In addition, Monitoring, Evaluation and Controlling plan should be ascertained.