For discussion
on 29 January 1999


Transport Department
New Subhead "Replacement of traffic control and surveillance system in Aberdeen Tunnel"

    Members are invited to approve a new commitment of $98.5 million for replacing the traffic control and surveillance system in Aberdeen Tunnel.


The existing traffic control and surveillance system in Aberdeen Tunnel is reaching the end of its serviceable life. We need to maintain the reliability of the system to ensure safety and avoid traffic congestion.


2. We propose to replace the traffic control and surveillance system in Aberdeen Tunnel at an estimated cost of $98.5 million.


3. The existing traffic control and surveillance system has been in service for more than 16 years. Recently, the Director of Electrical and Mechanical Services (DEMS) assessed the current state of the system and analysed the risk of malfunctioning. He found that many components of the system are showing signs of aging with reducing reliability and are reaching the end of their serviceable life. There were some 400 instances of minor component breakdowns in the past 12 months. Furthermore, due to technological advancement, the system computer has become obsolete and the manufacturer of the existing system has already informed us that supply of spare parts after 2002 cannot be guaranteed.

4. DEMS advised that delay in replacing the system is likely to give rise to more frequent failures as more components become malfunctioning. This may impair tunnel traffic control and affect the safety of tunnel users. In view of the long lead time of about 23 months required for delivery, installation and commissioning works, we consider it necessary to embark upon a project to replace the system as early as possible. Under the proposed project, we will replace the computer hardware and software, data communication, closed circuit television, automatic incident detection devices, signs, signals and other equipment of the surveillance system including the associated power supply and cabling work. In particular, we will introduce the notion of "client-server" into the new installation based on modern system architecture which can accommodate expansion of the system to meet future needs for traffic management. Subject to funding approval, we expect to start the project in April 1999 for completion in September 2002. We will phase the work and put in traffic management measures to avoid disrupting the flow of traffic through the tunnel during the replacement period.

5. As part of the replacement project, we propose to install additional electronic traffic information signs at approach roads to strengthen traffic management and advise motorists of the traffic condition well in advance to alleviate traffic congestion. The new system also adopts an integrated approach to incorporate updated technology design such as high availability cluster and fiber-optic transmission media.


6. We estimate that the capital cost of the project is $98.5 million, broken down as follows -

$ million
(a) Electronic, electrical and mechanical equipment installation
    (i) computer hardware and software
    (ii) data communication system
    (iii) closed circuit television system
    (iv) automatic incident detection system
    (v) signs, signals and other field equipment
    (vi) uninterruptible power supply
    (vii) testing, commissioning, training and documentation
    (viii) cables, accessories and spares
    (ix) dismantling, removal and disposal of replaced equipment

(b) Related equipment and installation
    (i) cable ducts
    (ii) mountings for gantry signs
    (iii) mountings for roadside signs and signals
    (iv) minor civil and building services works and contract preliminaries

(c) Project management charges by Electrical and Mechanical Services Trading Fund (EMSTF)(detailed breakdown at the Enclosure)

(d) Contingency [10% of (a) to (c)]



7. As regards paragraph 6(a), the cost of $71.6 million is for the dismantling and removal of the existing electronic and electrical system, the supply, installation, testing and commissioning of a new replacement system comprising computer hardware and software, data communication and television monitoring, automatic incident detection devices, various signs, signals and field equipment (e.g. over-height detectors, variable message signs, traffic lights, lane signals and remote control signs), and associated cabling work.

8. As regards paragraph 6(b), the cost of $9 million is for the related mechanical equipment and civil works such as cable ducting, gantry mounting for roadside signs and signals, building services and contract preliminaries.

9. As regards paragraph 6(c), the cost of $8.9 million is for paying the EMSTF engineering consultancy services. The trading fund will undertake the whole project including feasibility studies on the scope of project, definition of requirements, detailed functional design of installations, preparation of specifications, tender documentation and assessment, contract administration, site inspection, testing, commissioning and monitoring of defects liability. A computation of the charges is at the Enclosure. In the light of the Enhanced Productivity Programme, the trading fund has rationalised its costs and offered a reduction of about 9% from that computed on the basis of its standard charges.

10. Subject to Members' approval, we will phase the expenditure as follows -

Year$ million
1999-2000 1.8
2000-2001 9.1
2001-2002 52.0
2002-2003 35.6

Total 98.5


11. There will be no additional recurrent expenditure as the operation and maintenance costs of the traffic control and surveillance system will be met by the contractor managing the tunnel.

12. We will award the contract on a lump-sum fixed price basis.

13. The proposal will have no impact on toll charges.


14. Installed in 1981, the traffic control and surveillance system in Aberdeen Tunnel controls and monitors all aspects of traffic and surveillance facilities in the tunnel, such as traffic lights, variable warning and advisory signs, barriers and vehicle incident detectors. With the aid of closed circuit television cameras, the operators in the control room can respond to incidents immediately and make changes to the traffic plans and signal controls to suit site condition.


Transport Bureau
January 1999

Enclosure to FCR(98-99)69

Project Management Charges under
Electrical and Mechanical Services Trading Fund (EMSTF)
for Replacement of Traffic Control and
Surveillance System in Aberdeen Tunnel

% of charges on
project value

Project estimate for
electronic works
($ million)
($ million)
First $0.4 million 25% 0.4 0.10
Next $1.6 million 20% 1.6 0.32
Next $13 million 16.5% 13.0 2.15
Remainder $65.6 million 11% 65.6 7.22

_______ _______

Total 80.6 9.79

_______ _______

In the light of the Enhanced Productivity Programme, the EMSTF has rationalised its costs and offered about 9% reduction on the above computed fee. The fee to be charged by the trading fund after the reduction is $8.9 million.