---
title: "Urban road cross-section elements"
subject: "Transportation Engineering I"
chapter: 3
key: "semester_6/transportation_engineering_i:urban-road-cross-section"
source: https://www.bctengineer.com/q/semester_6/transportation_engineering_i/urban-road-cross-section
site: BCT Engineering
---

# Urban road cross-section elements

Transportation Engineering I · Chapter 3: Geometric Design of Highway

- Asked in: 2079 Chaitra, 8 marks; 2079 Jestha, 8 marks (asked 2 times)
- Video: [Highway cross section elements](https://www.youtube.com/watch?v=WX-mUQ4JMoE) — Civil Cafe
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/transportation_engineering_i/urban-road-cross-section
- Whole chapter: https://www.bctengineer.com/md/semester_6/transportation_engineering_i/chapter-3

## Question

With a typical drawing of an urban road cross section, explain in brief the various elements of an urban road cross section.

## Short answer

Urban road cross-section has carriageway lanes (3.0-3.5 m), median divider, kerb, footpath (min 1.5 m), parking lane (2-2.5 m), cycle track, drainage and utility lines under footpath, street furniture, right of way, building line, and sometimes service roads.

## Answer

An urban road has more elements than a rural road because it must also serve pedestrians, parking, drainage and utility services.

```text
|<--------------- Right of Way --------------->|
|footpath|green|  carriageway  |median| carriageway |green|footpath|
|  1.5-2m|    | L1  L2  parking|      | L1  L2      |     |        |
 =kerb==         ______/\______  (camber)           ==kerb==
 | drain below footpath / utilities                          |
```

#### Elements
1. **Carriageway:** lanes for vehicles; each lane 3.0-3.5 m (bus lane 3.5 m); the number of lanes depends on the capacity needed. Camber 2-2.5%.
2. **Median (divider):** separates opposing flows on multi-lane roads; may carry trees and street lights; minimum 1.2 m (preferably more).
3. **Kerb:** raised edge (100-150 mm) separating the carriageway from the footpath; it also guides the drainage to the gully.
4. **Footpath (sidewalk):** for pedestrians, minimum 1.5 m (more in busy areas), with a slight cross slope for drainage.
5. **Parking lane:** 2.0-2.5 m wide for parallel parking along the kerb.
6. **Cycle track:** a separate path, usually 2.0 m for two-way use; protects cyclists.
7. **Drainage:** storm sewers, gully pits, or covered drains under the footpath.
8. **Utilities:** water, sewer, electric and telecom lines under the footpath or green strip.
9. **Street furniture:** street lights, signs, bus stops, benches, trees and green verge.
10. **Right of way and building line:** the right of way is the total corridor; buildings must be set back behind the building line for light, safety and future widening.
11. **Service roads / frontage roads:** run parallel to the main road for local access.

## Check yourself

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

1. Why does an urban road cross section have more elements than a rural road?
   A. Because the speeds are higher
   B. Because of pedestrians, parking, drainage and utility services
   C. Because urban roads never have a camber
   D. Because urban roads have no right of way
   Answer: B. Pedestrians, parking, drainage and utilities require footpaths, parking lanes, drains and service space. (Key point: Why urban roads have more elements)

2. What is the function of a kerb in an urban road?
   A. It separates the carriageway from the footpath and guides drainage to the gully
   B. It carries utility lines
   C. It provides the camber
   D. It marks the building line
   Answer: A. The kerb is a raised edge (100-150 mm) separating the carriageway from the footpath and guiding drainage. (Key point: Kerb)

3. What is the minimum footpath width given in the answer?
   A. 0.5 m
   B. 1.5 m
   C. 3.0 m
   D. 2.5 m
   Answer: B. A footpath is at least 1.5 m, more in busy areas, with a slight outward slope. (Key point: Footpath)

4. Why are buildings set back from the building line?
   A. To increase carriageway camber
   B. To provide parking only
   C. To allow lighting of the road surface only
   D. For light, safety and future widening
   Answer: D. The building line keeps construction away for light, safety and future widening of the corridor. (Key point: Building line)

## Related in Transportation Engineering I

- [Elements of cut and fill cross-section](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Acut-fill-cross-section) — Transportation Engineering I, chapter 3
- [Typical cross-sections of hill roads](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Ahill-cross-sections) — Transportation Engineering I, chapter 5, asked 9×
- [Cross-sectional elements of a highway](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Across-section-elements) — Transportation Engineering I, chapter 3, asked 2×
- [Major urban road patterns](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Aurban-road-patterns) — Transportation Engineering I, chapter 1, asked 5×
- [Urban road networks and ring road](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Aurban-network-ring-road) — Transportation Engineering I, chapter 1, asked 2×
- [Simple circular curve elements and chainages](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3An-64s-simple-curve) — Transportation Engineering I, chapter 3

## Related in other subjects

- [Apparent dip in cross-section drawing](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aapparent-dip-in-crosssection-drawing) — Engineering Geology I, chapter 5
- [Canal cross-section in cutting and filling](https://www.bctengineer.com/question.md?key=semester_6%2Firrigation_and_drainage_engineering%3Acanal-cross-section-cut-fill) — Irrigation and Drainage Engineering, chapter 3, asked 3×
- [Transition elements; non-typical 3d element](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Atm-not-typical) — Engineering Chemistry, chapter 5
- [Hill road earthwork with cross sections](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Ahill-road-u-cross-sections) — Estimating and Costing, chapter 6