Fahud-Qarn Alam Road Safety Audit Report Sasa

7/28/2019 Fahud-Qarn Alam Road Safety Audit Report Sasa

1/12

1

For:

Fahud-Qarn Alam road

Annex to: Oman North Graded Road Improvement Project

Annex 1: The road survey reports from RSST Controller North for the

immediate action for improving the layout of the road and the traffic signs

Muscat

23.01.2012


2/12

2

Document Control Sheet

Project Name: North Graded Road Improvement ProjectProject Number:Document /

Report Title: Fahud-Qarn Alam graded road improvement option appraisal Issue 1Document /

Report Number:Issue Status/Amendment Prepared Reviewed Approved

Issue 1

Document reviewed for

Public ExhibitionName:

Sasa Kocic

Signature:

Sasa Kocic

Date: 23/01/12

Name:

Fayel Zarei

Signature:

FAYEL ZAREI

Date: 24/01/12

Name:

Signature:

Date:

Document reviewed Name:

Signature:

Date:

Name:

Signature:

Date:

Name:

Signature:

Date:

Document reviewed and

Additional material inserted Name:

Signature:

Date:

Name:

Signature:

Date:

Name:

Signature:

Date:


3/12

3

1. Foreword

1.1.1. The purpose of this document is to summarize the work

carried out by ONE and RSST with regard to the issues of

tackling the road safety issues on the graded road from

Fahud to Qarn Alam, which was indicated as the priority road

for the upgrading into the asphalt road by the on-site

engineers and later identified by the TOPSIS method as the

priority road for the improvement.

1.1.2. It outlines the advantages and disadvantages of the options

considered for the improvement of the road makesrecommendations to be brought forward to future decision on

the approval of the budget for the upgrading the road into the

asphalt road or deciding on the different improvement

measures to tackle the safety issues raised.


4/12

4

2. Road Appraisal

2.1. Introduction

2.1.1. The Fahud-Qarn Alam road is the arterial road between the

Fahud and Qarn Alam cluster in the PDO concession area,

predominantly used by the PDO and related contractors for

the transport and commuting, with approximately 117

vehicles per hour using this road.

The road is 125km long and going through the mostly rolling

(hilly) terrain, with several sections on the steep gradients.

Figure 1: Road inrelation to the PDO

Locations


5/12

5

2.1.2. At present the road is a graded road with varying width, andwith safety lanes on the most of the road sections.

The road is maintained as per the PDO requirements and the

budget constraints, but the proper requirement, as pre thestandards and directives it is that the whole road should be re-sheeted four times in a year.

Regular re-sheeting is not carried out, but only the work inrelation to the most damaged areas.

2.1.3. As part of the review process the roads indicated by the

Operation and Engineering teams have been classified and

prioritized by the use of TOPSYS and the criteria of numberof RTA, price for upgrade, price for the maintenance and the

traffic counts.

The Fahud-Qarn Alam graded road came to be the top one in

these criteria mentioned previously.

Figure 2: Priority of the roads by

TOPSYS


6/12

6

2.1.4. The RTA data was collected for the previous three years and

the analysis of this data has provided the following:

RTA Date Type of RTA Main cause Contributory factor

18.09.2009 Rollover Driver error

Road layout: consecutive bends,steep decline,

Road Surface: difference in friction

factors

29.07.2010 RolloverExcessive

speed


factors

09.09.2010 Rollover Tyre burstRoad Surface: difference in friction

factors

08.10.2010 Rollover

Excessive

speed


factors


speed


factors


speed


factors due to the wet and muddy

surface of the road

21.04.2011 Rollover Tyre burst

Road layout: rolling terrain


factors


speed


factors, holes and cracks in the road

surface


speed

Missing traffic signs


factors

The evidences collected from the RTA that happened on this

road indicate that the road surface and the road layout play a

significant part as the main contributory factors in all of the

RTA that have happened.

The main problem is indicated in the following picture, and it

represents the issue that is common to all of this RTA-s.


7/12

7

Figure 3: Typical road surface composition for the Fahud-Qarn Alam graded

road

The road surface cannot be compacted enough to provide a

same friction on all of the wheels of the vehicle, therefore it

has the same effect as the water ponds on the asphalted

roads, creating the difficulty for the driver to keep his vehicle

in line, and encouraging the road users to try to drive on the

whole carriageway, instead of driving only on their side of the

road.

Also, the dispersion of these RTA shows that intervention on

one location would not be sufficient, considering that the RTA

locations are dispersed along the whole road.

The measure of the re-grading or re-sheeting the road would

also require a lot of work and it would also affect the usage of

this road, considering that the re-sheeting of the graded road

uses water etc., therefore also creating the hazard of creatinga wet and muddy road surface while trying to improve the

condition of the road surface itself.

The following pictures are from the RTA-s that happened

during the 2011, and they indicate the road surface condition

at the time of the RTA:


8/12

8

The pictures are from different RTA-s but they show almost

the same conditions of the road layout: straight section,

almost level terrain, therefore the application of the traffic

signs would not be appropriate because there is no specific

danger or hazard to warn the road users of.

This kind of interventions can be applied on the approaches

to the graded road roundabout close to Qarn Alam, or on the

approach to the consecutive bends near Fahud, but on the

straight sections of road it would not give any additional

information and would not provide the results needed.

Further, the RTA locations on the road indicate that the area

of intervention would be 98km which is almost the whole road

length.


9/12

9

The intervention in regards to the hazard of the consecutive

bends near Fahud, if the appropriate solution for the graded

road is to be constructed would also require a lot of

investment, considering the earthwork needed for the

appropriate profile to be achieved.

The following pictures indicate the difference in the levels of

the existing terrain and the proposed level.

And also the 3D representation of the corridor of the graded

road, with proper safety lanes is shown to present the future

layout.


10/12

10

Difference in the levels would be 16.3m, as indicated in the

existing ground (green) and the future ground (red) levels

presented below:

The corridor would have to be as presented in the following

picture, if terraced walls are not introduced (the picture is for

presentation purposes only, the detail design need to be

done in order to get the accurate layout and the quantities for

the work needed.


11/12

11

3. Conclusion

The Fahud-Qarn Alam graded road should be upgraded into

the asphalt road considering the traffic volumes, cost for the

maintenance and the fact that most of the RTA-s thathappened on a straight road, almost level terrain and the

soft measures of the driver training and the traffic signs

placement will not be sufficient.

This is of course the justification for the Fahud-Qarn Alam

road only and it cannot be generally applied for upgrading of

any other graded road, except as a reference, considering

that other graded roads have their own characteristics in

terms of layout, RTA data and usage.


12/12

12

Documents

Fahud-Qarn Alam Road Safety Audit Report Sasa