Transportation Engineering, Pavement and
Geometric Design
Project Re-Submission
Year 2025
Title: Upgrading of a 3.74 km-D885 Road from a Gravel Road to a
Standard Surface 2-lane, two-way road.
0027 61 774 8540
1
, Declaration
I, ……………………………………………, ID No/Passport No…………………hereby
declare that this project is my own work
SIGNED………………………………………………………….
NAME……………………………………………………………
STUDENT NUMBER……………………………………………
CONTACT NUMBERS:
TEL...........................................................................................
CELL………………………………………………………………..
2
, Transportation, Pavement and Geometric Design (TPG3700)
DESIGN PROJECT – 2025
PROJECT MENTOR FORM
PLEASE COMPLETE IN CLEAR BLOCK LETTERS AND SUBMIT
AS PART OF THE PROJECT PROPOSAL
Student initial and surname: ............................................................
Student no.: ......................................……………………
Tel no.: ..................................................... (work)
Cell phone no.: ………………………………………………..
UNISA e-mail address: ....................................................
Subject name and Mentor’s details
code
Transportation, Initials & surname: Signature of
Pavement and mentor
Tel no.:
Geometric Design
(TPG3700) E-mail address:
I confirm that I have discussed all aspects of the project with the mentor
from………………………………………………..(Name of institution) and that
UNISA will in no way be liable for any costs with respect to this project.
______________________ ______________
SIGNATURE OF LEARNER DATE
3
,Table of Contents
1.0 INTRODUCTION .............................................................................................................. 5
1.1 Project Overview ........................................................................................................... 5
1.2 Existing road description.............................................................................................. 6
1.3 Design data .................................................................................................................... 7
2.0 GEOMETRIC DESIGN (MANUAL CALCULATIONS) .............................................. 8
2.1 Horizontal curve ............................................................................................................ 8
2.1.1 Horizontal curve: Excel calculator tool ............................................................. 10
3.0 PAVEMENT STRUCTURE DESIGN .......................................................................... 11
3.1 Design standards .................................................................................................... 11
3.2 Subgrade delineation and design CBR determination .......................................... 11
3.3 Subgrade design ......................................................................................................... 12
3.4 Pavement design alternatives ................................................................................... 14
3.4.1 Granular base design .......................................................................................... 14
3.4.2 Cement treated base ........................................................................................... 16
3.4.3 Hot Mix Alsphalt base ......................................................................................... 17
4.0 DRAINAGE CONCEPTUAL DESIGN ........................................................................ 19
5.0 SOFTWARE-AIDED GEOMETRIC DESIGN ............................................................ 20
5.1 Design procedure........................................................................................................ 20
6.0 CONCLUSION ................................................................................................................ 29
7.0 REFERENCES................................................................................................................ 30
8.0 APPENDIX 1: DESIGN DRAWINGS .......................................................................... 31
4
,1.0 INTRODUCTION
1.1 Project Overview
The most appropriate location, alignment, and shape of a highway are selected during
the design stage. Highway design involves the consideration of three major factors
(human, vehicular, and roadway) and how these factors interact to provide a safe
highway. Human factors include reaction time for braking and steering, visual acuity
for traffic signs and signals, and car-following behavior. Vehicle considerations include
vehicle size and dynamics that are essential for determining lane width and maximum
slopes, and for the selection of design vehicles. Highway engineers design road
geometry to ensure stability of vehicles when negotiating curves and grades and to
provide adequate sight distances for undertaking passing maneuvers along curves on
two-lane, two-way roads.1
The main purpose of this project is to upgrade road D885 from Gravel to a standard
surface 2-lane, two-way road. The portion of the road to be designed is 3.74 km
starting from Chainage 44.400km to Chainage 48.140km. The proposed road upgrade
forms an intersection with road D3600. The Road connects to Road D3600 with Road
R519, to Mokopane and Lebowakgomo. D885 passes through several commercial
farms and is an access to a local lime mine.In addition, a conceptual design of the
drainage stormwater along the proposed road design is going to be carried out. This
report will also include manual calculations of horizontal curve and a vertical curve
according to TRH17 Geometric Design of Rural Roads and SANRAL Road Drainage
manual.
1
Highway engineering." McGraw-Hill Concise Encyclopedia of Science and Technology. New York: McGraw-Hill,
2006.
5
, 1.2 Existing road description
The proposed street upgrade is situated within the jurisdictions of Lepelle Nkumpi
(LIM355) and Mookgopong (LIM356) municipalities under Capricorn and Waterberg
Districts of the Limpopo Province (LP). This project is located approximately 70 km
Southeast of Mokopane.
Fig 1. D885 Gravel Road in Limpopo
The project involves upgrading Road D885 in the Limpopo Province from a gravel
surface to a standard surfaced 2-lane, two-way road. The road currently serves as an
important link for rural communities, providing access to social amenities, agricultural
markets, schools, and healthcare facilities. However, the existing gravel condition
often leads to poor ride quality, dust pollution, high vehicle operating costs, and
accessibility challenges during rainy seasons.
Upgrading the D885 to a standard surfaced road will:
1. Improve road safety and travel reliability for both passenger and freight
vehicles.
2. Enhance connectivity between rural communities and larger towns, boosting
local economic activities.
3. Reduce vehicle maintenance costs and travel times.
6
Geometric Design
Project Re-Submission
Year 2025
Title: Upgrading of a 3.74 km-D885 Road from a Gravel Road to a
Standard Surface 2-lane, two-way road.
0027 61 774 8540
1
, Declaration
I, ……………………………………………, ID No/Passport No…………………hereby
declare that this project is my own work
SIGNED………………………………………………………….
NAME……………………………………………………………
STUDENT NUMBER……………………………………………
CONTACT NUMBERS:
TEL...........................................................................................
CELL………………………………………………………………..
2
, Transportation, Pavement and Geometric Design (TPG3700)
DESIGN PROJECT – 2025
PROJECT MENTOR FORM
PLEASE COMPLETE IN CLEAR BLOCK LETTERS AND SUBMIT
AS PART OF THE PROJECT PROPOSAL
Student initial and surname: ............................................................
Student no.: ......................................……………………
Tel no.: ..................................................... (work)
Cell phone no.: ………………………………………………..
UNISA e-mail address: ....................................................
Subject name and Mentor’s details
code
Transportation, Initials & surname: Signature of
Pavement and mentor
Tel no.:
Geometric Design
(TPG3700) E-mail address:
I confirm that I have discussed all aspects of the project with the mentor
from………………………………………………..(Name of institution) and that
UNISA will in no way be liable for any costs with respect to this project.
______________________ ______________
SIGNATURE OF LEARNER DATE
3
,Table of Contents
1.0 INTRODUCTION .............................................................................................................. 5
1.1 Project Overview ........................................................................................................... 5
1.2 Existing road description.............................................................................................. 6
1.3 Design data .................................................................................................................... 7
2.0 GEOMETRIC DESIGN (MANUAL CALCULATIONS) .............................................. 8
2.1 Horizontal curve ............................................................................................................ 8
2.1.1 Horizontal curve: Excel calculator tool ............................................................. 10
3.0 PAVEMENT STRUCTURE DESIGN .......................................................................... 11
3.1 Design standards .................................................................................................... 11
3.2 Subgrade delineation and design CBR determination .......................................... 11
3.3 Subgrade design ......................................................................................................... 12
3.4 Pavement design alternatives ................................................................................... 14
3.4.1 Granular base design .......................................................................................... 14
3.4.2 Cement treated base ........................................................................................... 16
3.4.3 Hot Mix Alsphalt base ......................................................................................... 17
4.0 DRAINAGE CONCEPTUAL DESIGN ........................................................................ 19
5.0 SOFTWARE-AIDED GEOMETRIC DESIGN ............................................................ 20
5.1 Design procedure........................................................................................................ 20
6.0 CONCLUSION ................................................................................................................ 29
7.0 REFERENCES................................................................................................................ 30
8.0 APPENDIX 1: DESIGN DRAWINGS .......................................................................... 31
4
,1.0 INTRODUCTION
1.1 Project Overview
The most appropriate location, alignment, and shape of a highway are selected during
the design stage. Highway design involves the consideration of three major factors
(human, vehicular, and roadway) and how these factors interact to provide a safe
highway. Human factors include reaction time for braking and steering, visual acuity
for traffic signs and signals, and car-following behavior. Vehicle considerations include
vehicle size and dynamics that are essential for determining lane width and maximum
slopes, and for the selection of design vehicles. Highway engineers design road
geometry to ensure stability of vehicles when negotiating curves and grades and to
provide adequate sight distances for undertaking passing maneuvers along curves on
two-lane, two-way roads.1
The main purpose of this project is to upgrade road D885 from Gravel to a standard
surface 2-lane, two-way road. The portion of the road to be designed is 3.74 km
starting from Chainage 44.400km to Chainage 48.140km. The proposed road upgrade
forms an intersection with road D3600. The Road connects to Road D3600 with Road
R519, to Mokopane and Lebowakgomo. D885 passes through several commercial
farms and is an access to a local lime mine.In addition, a conceptual design of the
drainage stormwater along the proposed road design is going to be carried out. This
report will also include manual calculations of horizontal curve and a vertical curve
according to TRH17 Geometric Design of Rural Roads and SANRAL Road Drainage
manual.
1
Highway engineering." McGraw-Hill Concise Encyclopedia of Science and Technology. New York: McGraw-Hill,
2006.
5
, 1.2 Existing road description
The proposed street upgrade is situated within the jurisdictions of Lepelle Nkumpi
(LIM355) and Mookgopong (LIM356) municipalities under Capricorn and Waterberg
Districts of the Limpopo Province (LP). This project is located approximately 70 km
Southeast of Mokopane.
Fig 1. D885 Gravel Road in Limpopo
The project involves upgrading Road D885 in the Limpopo Province from a gravel
surface to a standard surfaced 2-lane, two-way road. The road currently serves as an
important link for rural communities, providing access to social amenities, agricultural
markets, schools, and healthcare facilities. However, the existing gravel condition
often leads to poor ride quality, dust pollution, high vehicle operating costs, and
accessibility challenges during rainy seasons.
Upgrading the D885 to a standard surfaced road will:
1. Improve road safety and travel reliability for both passenger and freight
vehicles.
2. Enhance connectivity between rural communities and larger towns, boosting
local economic activities.
3. Reduce vehicle maintenance costs and travel times.
6
