---
title: "Define highway drainage"
subject: "Transportation Engineering I"
chapter: 4
key: "semester_6/transportation_engineering_i:define-highway-drainage"
source: https://www.bctengineer.com/q/semester_6/transportation_engineering_i/define-highway-drainage
site: BCT Engineering
---

# Define highway drainage

Transportation Engineering I · Chapter 4: Highway Drainage

- Asked in: 2079 Chaitra, 2 marks; 2077 Chaitra, 1 marks; 2072 Ashwin; 2064 Poush (old course), 1 marks; 2063 Kartik (old course), 1 marks (asked 5 times)
- Video: [Highway Drainage - Transportation Engineering - I](https://www.youtube.com/watch?v=74_mP-_38zk) — Ekeeda
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/transportation_engineering_i/define-highway-drainage
- Whole chapter: https://www.bctengineer.com/md/semester_6/transportation_engineering_i/chapter-4

## Question

Define highway drainage (system).

## Short answer

Highway drainage is the system of structures and channels that removes surface and sub-surface water from the road and surroundings to keep pavement and subgrade stable, dry, and safe. It comprises surface drainage (camber, side drains), cross drainage (culverts, bridges), and sub-surface drainage (water table control).

## Answer

**Highway drainage** is the process of removing and diverting surface water and sub-surface water from the road and its surroundings, by a system of structures and channels, so that the pavement and the subgrade stay stable, dry and safe for traffic.

The drainage system collects rainwater falling on the carriageway, shoulders, slopes and the catchment above the road, and transports it to a safe outlet. It has three parts:

- **Surface drainage** (camber, side drains, catch drains)
- **Cross drainage** (culverts, causeways, minor bridges)
- **Sub-surface drainage** (control of water table, seepage and capillary water)

## Check yourself

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

1. Highway drainage is best defined as:
   A. Providing water supply to roadside
   B. Removing and diverting surface and sub-surface water so pavement and subgrade stay stable and dry
   C. Only the camber of the pavement
   D. Construction of bridges
   Answer: B. It is the removal and diversion of surface and sub-surface water by structures and channels. (Key point: Definition)

2. Which three parts make up highway drainage?
   A. Culvert, bridge and causeway
   B. Camber, kerb and shoulder
   C. Rural, urban and hill
   D. Surface, cross and sub-surface drainage
   Answer: D. The system has surface, cross and sub-surface drainage. (Key point: Parts of the system)

3. Which structures belong to cross drainage?
   A. Camber and side drains
   B. Culverts, causeways, minor bridges
   C. Catch drains
   D. Trench drains
   Answer: B. Cross drainage carries water across the road using culverts, causeways and minor bridges. (Key point: Cross drainage example)

## Related in Transportation Engineering I

- [Components of highway drainage system](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Adrainage-components) — Transportation Engineering I, chapter 4
- [Requirements of highway drainage](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Arequirements-highway-drainage) — Transportation Engineering I, chapter 4, asked 6×
- [Importance of highway drainage](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Adrainage-importance) — Transportation Engineering I, chapter 4, asked 4×
- [Classification of highway drainage](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Aclassify-highway-drainage) — Transportation Engineering I, chapter 4
- [Surface drainage system](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Asurface-drainage-system) — Transportation Engineering I, chapter 4
- [Cross drainage structures and types](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Across-drain-types) — Transportation Engineering I, chapter 4, asked 3×

## Related in other subjects

- [Layout planning of surface drainage system](https://www.bctengineer.com/question.md?key=semester_6%2Firrigation_and_drainage_engineering%3Asurface-drainage-layout-planning) — Irrigation and Drainage Engineering, chapter 9
- [Need of crash studies; highway lighting design](https://www.bctengineer.com/question.md?key=semester_7%2Ftransportation_engineering_ii%3Acrash-studies-need-highway-lighting-design) — Transportation Engineering II, chapter 1