The document summarizes a student presentation on the impact of climbing lanes on travel speeds and time spent following on two-lane highways. The presentation includes sections on background, problem statement, objectives, scope, literature review, methodology, results and analysis, and conclusions. The results show that average travel speeds increased and percent time spent following decreased with the addition of climbing lanes. However, truck speeds reduced on grades due to steepness. The conclusions recommend further models be developed to determine level of service on two-lane highways in Uganda based on Highway Capacity Manual estimations.

1. Impact of Climbing Lanes on Average Travel
Speed and Percent Time Spent Following on Two
lane highways
Presented by:
Lukwago Mark 11/U/9998/PS
Candia John Bosco 11/U/22281/PSA
Main Supervisor: Mr. Godfrey Mwesige
Co-Supervisor: Miss. May Namutebi
[ Source: www..com Dece 15th 2015, 5:00pm ]

2. PRESENTATION OUTLINE
 Background and justification
 Problem statement
 Objectives
 Scope
 Literature review
 Methodology
 Results and Analysis
 Conclusions & recommendations
4/20/2020

3. Introduction
Background and justification
~ Two-lane highways constitute a large percentage of the total road network in
Uganda (National Roads 10,000 Km, District Roads 27,500 Km and Urban
Roads 4,800 Km).
~ Fast moving vehicles get delayed as they are unable to overtake slow moving
vehicles hence they move in platoons.
~ HGV induce frequent gaps of excessive length both in front and behind
themselves thereby affecting the speed of vehicles and their spacing
~ Climbing lanes separate slow moving vehicles from the traffic stream in the
through lane.
- Increase roadway capacity
- improve safety
- Eliminate queuing/smooth traffic operation

4. Introduction cont’d...
Problem statement
~ Trucks exhibit low levels of up-hill climbing performance on highways.
~ At uphill grades of sufficient length and steepness their speed loss impedes the traffic
flow, reduces highway capacity.
~ The increased movement and use of larger and heavier trucks on the majority of
roadway facilities results into platooning of vehicles hence reduced level of service of the
road.
Problem statement
~ Trucks exhibit low levels of up-hill climbing performance on highways.
~ At uphill grades of sufficient length and steepness their speed loss impedes the traffic
flow, reduces highway capacity.
~ The increased movement and use of larger and heavier trucks on the majority of
roadway facilities results into platooning of vehicles hence reduced level of service of the
road.
Scope
Geographical scope
~ Kampala-Jinja road at Buwoola.
~ Kampala-Mityana road at Zigoti- Kito.
Time scope
~ 6 months

5. Objectives
Main objective
~ Assess impact of climbing lanes on average travel speed and queuing on
two-lane highways.
Specific Objectives
~ To assess the impact of the climbing lane on the average travel speeds.
~ To assess the impact of the climbing lane on reduction of queues behind
slow vehicles.
~ To determine geometric characteristics of climbing lanes that yield
optimal increase in average travel speeds and queue reduction i.e. lane
width, length, grade on which the climbing lane is provided.
Introduction cont’d...

6. Literature review
Introduction
Climbing lane
~ An additional outside lane added to a single or dual carriageway in order to
improve overtaking opportunities, capacity and safety (MoWT, geometric design
manual (Vol. 1, 2010)
Source: RPDM.,(2002). retrieved from http://www.RoadPlanninganddesignmanual.com ,
last accessed 20th November 2014
~ Climbing Lane Warrants (MoWT, 2010, AASHTO, 2010, Highway Geometric Design Guide ,2000)
~ Geometric Features of a Climbing lane (HCM, 2000)
~ Other factors influencing travel speeds
~ Formulas for analysis
23/02/2015

7. Performance analysis of climbing lanes
Investigation of performance measure on two lane highways [Al-Kaisy
and Karjala (2008)]
-Observed follower density to be the most promising service measure on two
lane highway.
Estimating PTSF based on the total flow, percentage of no-passing zones
and directional distribution of traffic., [Luttinen (2001)]
-Developed models which resulted into lower value of PTSF than that
estimated by HCM.
-This overestimates is because HCM assumed an autogenously traffic
characteristic over the two lane highway as opposed to the actual
Literature Review cont’d...

8. Methodology
4/20/2020
Preliminary
Examination
Field work
Data Collection
Video Observation
Data
Preparation
Estimation of
ATS & PTSF
Statistical
Analysis
Geometric Data
Design Speed
Grades
Lane & Shoulder Width
Length

9. Results and Analysis

10. Results and Analysis contd....
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1 2 3 4 5 6 7 8
ATS
15 minute Interval
Graph of ATSd and ATSpl
ATSd ATSpl
0.00
20.00
40.00
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100.00
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1 2 3 4 5 6 7 8
PTSF
15 minute Interval
Graph of PTSFd and PTSFpl
PTSFd PTSFpl
Climbing
lane
Length
(m)
Width
(m)
Through
lane
width
(m)
Shoulder
width
(m)
Entry
taper
(m)
Exist
taper
(m)
Grade
(%)
Buwoola 1400 3.5 3.5 1.5 300 300 4
Zigoti 1400 3.3 3.3 1.0 300 300 4
0
20
40
60
80
100
120
10
20
30
40
50
60
70
80
90
100
More
Frequency
Speeds in the middle of Climbing Lane
Histogram
Frequency

11. Conclusions & recommendations
Conclusions
― Small vehicles speeds increased in the middle of the climbing lane (35-60km/hr to 65-
85km/hr av.).
―Truck speeds reduced due to the presence of a steep grade in the middle of the climbing
lane (38 km/hr av.)
―ATS increased with the inclusion of a climbing lane
―PTSF hence queuing reduced insignificantly from the middle of the climbing lane to
downstream beyond 1000km
―Geometric characteristics of the climbing lane had an insignificant impact on small vehicle
speeds and impacted greatly the truck speeds.
Recommendations
―Models based on the HCM estimations to determine the level of service of two lane high
ways in Uganda be developed.
―Traffic management strategies like education drivers on rightful use of road infrastructure be
devised and implemented
―Bays and parking zones along the road should be provided at access road points and built up
areas.
― Further studies for climbing lanes with a bias in driver and vehicle control be developed
―Climbing lane sections should be properly marked with sufficient road furniture.

12. THANK YOU