---
title: "Region, band, corridor, alignment in map study"
subject: "Transportation Engineering I"
chapter: 2
key: "semester_6/transportation_engineering_i:map-study-terms"
source: https://www.bctengineer.com/q/semester_6/transportation_engineering_i/map-study-terms
site: BCT Engineering
---

# Region, band, corridor, alignment in map study

Transportation Engineering I · Chapter 2: Highway Alignment and Engineering Survey

- Asked in: 2064 Poush (old course), 2+2+2+2 marks
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/transportation_engineering_i/map-study-terms
- Whole chapter: https://www.bctengineer.com/md/semester_6/transportation_engineering_i/chapter-2

## Question

Define and describe the terms region, band, corridor and alignment with respect to the map study for highway route identification.

## Short answer

Route location narrows from region (whole area between terminals) to band (region excluding major barriers, several km wide) to corridor (narrower strip with probable alignments, hundreds of meters to km wide) to alignment (exact centerline fixed after surveys). Each step uses progressively detailed map study and field surveys to refine the route.

## Answer

In route location the study narrows step by step from the largest area to the smallest.

- **Region:** the whole area, usually a large one, between the two terminals and including all the controls, within which the route can be placed. It is identified from small-scale maps, e.g. the zone between Kathmandu and Pokhara.
- **Band:** the part of the region left after the large barriers (high mountains, big lakes, reserved forests) are excluded. It contains the feasible routes and is found by studying maps and aerial photos. Its width is typically several kilometres.
- **Corridor:** a narrower strip within the band that contains the probable alignments, found after more detailed map study and reconnaissance. Its width is a few hundred metres to a kilometre.
- **Alignment:** the exact centre line of the road within the corridor, with all its curves and gradients, fixed after the preliminary and final location surveys.

```text
 Region  >  Band  >  Corridor  >  Alignment
 (largest)                         (one line)
```

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is the region?
   A. The exact centre line
   B. A narrow strip a few hundred metres wide
   C. The part left after barriers are removed
   D. The whole large area between the terminals including all controls
   Answer: D. Region is the large area between terminals within which the route can lie. (Key point: Region)

2. How is the band defined?
   A. The part of the region left after removing large barriers like high mountains, lakes and reserved forests
   B. The same as the alignment
   C. A strip of 10 m
   D. The full region
   Answer: A. Band contains feasible routes after big barriers are excluded. (Key point: Band)

3. The corridor is:
   A. Several kilometres wide
   B. A narrower strip within the band, a few hundred metres to a kilometre wide
   C. The whole region
   D. One centre line
   Answer: B. Corridor is a narrow strip with probable alignments. (Key point: Corridor width)

4. The alignment is:
   A. A wide band
   B. The map scale
   C. The exact centre line in the corridor with curves and gradients, fixed after preliminary and final surveys
   D. The whole region
   Answer: C. Alignment is the final centre line. (Key point: Alignment)

## Related in Transportation Engineering I

- [Requirements of ideal highway alignment](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Aalignment-requirements) — Transportation Engineering I, chapter 2, asked 12×
- [Factors controlling highway alignment](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Aalignment-factors) — Transportation Engineering I, chapter 2, asked 12×
- [Definition of highway alignment](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Adefine-alignment) — Transportation Engineering I, chapter 2, asked 4×
- [Importance of map study](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Amap-study) — Transportation Engineering I, chapter 2
- [Structure of route location process](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Astructure-route-location) — Transportation Engineering I, chapter 2, asked 5×
- [Stages of engineering survey for alignment](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Asurvey-stages) — Transportation Engineering I, chapter 2, asked 7×

## Related in other subjects

- [Diagonal scale: Kathmandu-Pokhara highway map](https://www.bctengineer.com/question.md?key=semester_3%2Fsurveying_i%3Adiagonal-scale-kathmandu-pokhara-224) — Surveying I, chapter 1, asked 2×
- [Case study: plan, feasibility and ROI](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Acs-2075chaitra) — Instrumentation II, chapter 10
- [Case study: feasibility, drawbacks, convincing](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Acs-2072kartik-feasibility) — Instrumentation II, chapter 10
- [Tunnel alignment from three boreholes](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Atunnel-alignment-three-boreholes) — Engineering Geology II, chapter 6