3 Project Description
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3 PROJECT DESCRIPTION 3.1 General The Port Louis conurbation, is currently experiencing severe morning and afternoon traffic congestion, estimated to cost the Mauritian economy around Rs 2 billion annually. The Road Development Authority (RDA), Ministry of Public Infrastructure and Land Transport of the Government of Mauritius is thus implementing a Road Decongestion Programme, entailing the establishment of a network of roads, in order to alleviate the severe traffic congestion being experienced along the Port Louis-Curepipe corridor and around Port Louis itself. The Government of Mauritius (GOM) has set a high priority for development of road infrastructure to support the achieved and planned pace of economic growth. The main focus is set on the National Road Decongestion Programme to provide an effective approach of decongestion of the road network in Mauritius. The whole extent of Port Louis to St Jean Road (A1) is heavily congested throughout the day and traffic jam reach an unbearable level during peak hours. Severe traffic congestion occurs along the M1 Motorway from Caudan waterfront through the M2 Motorway towards Quay D and Mer Rouge Roundabouts, especially during peak times. Also, the traffic volume of the inner roads in Port Louis City has been largely exceeded its capacity and acute traffic jams occur during business hours, especially in the vicinity of Place d'Armes. Therefore, in order to ease the traffic congestion, a re-design of the Pont Fer, Jumbo and Dowlut Roundabouts as part of the Road Decongestion Programme (RDP) has been prioritised. The proposed project has been selected based on the recommendations of traffic modelling performed by KEC whose parameters are considered to remain valid as well as the following parameters: Function Cost Constructability Social Impact Environmental Impact Maintenance. The project description, as given in this chapter, are extracts from the Front End Engineering Design Report (FEED) prepared by KEC. EIA GSJ at Pont Fer / Jumbo / Dowlut Roundabouts 3-1 May 2017 M191/GSJ/3.1 3.1 Project Description 3.1.1 Project Location The Grade Separated Junctions (GSJ) involving three roundabouts at Pont Fer, Jumbo and Dowlut display typical characteristics of the downtown road and are located in the heart of the busiest downtown area in Mauritius. The Sodnac Link Road provides a direct connection from the town of Quatre Bornes to the Phoenix Mall, Offices, Industrial Zone in the Pont Fer area and on a broader scale to the M1 motorway in the Southern direction. The Current Traffic Volume witnesses more than 50,000 vehicles/day. Whereas according to international standards a daily traffic volume of 25,000 vehicles/day is recommended for a 2 lane roundabout. Accordingly, severe traffic congestion is observed at Pont Fer and Jumbo Roundabouts. 3.1.2 Main Line Carriageways The M1 Motorway at Phoenix Roundabout is a dual carriageway with 6 lanes to northbound and dual carriage way with 4 lanes to southbound. The B63 road from Jumbo Roundabout, is a dual carriageway with 4 lanes. As a method for relieving the congestion around Pont Fer roundabout, one lane as an independent road is currently in operation for Airport bound from Port Louis and Port Louis bound from Vacoas. 3.1.3 Roundabouts Concerned The distances between the Roundabouts are: (1) 500m between Pont Fer and Dowlut. (2) 350m between Pont Fer and Jumbo. All 3 roundabouts; Pont Fer, Jumbo and Dowlut, have 2 lanes in operation. The close proximity between the roundabouts increases the traffic congestion from one intersection to the other. 3.1.4 Operation of Pont Fer Roundabout The Pont Fer Roundabout operates with 2 lanes. However, the single lane as an independent road for Airport bound from Port Louis adds an additional lane to the part of the roundabout. This results in a partial 3 lane operation, which then requires the approaching traffic into the factory area to turn and cut across 3 lanes simultaneously. This raises an alarm in the road safety and seeks an immediate remediation. 3.2 Brief Project Description The proposed project consists of the following: Construction of the Pont Fer viaduct which is shown schematically in Figure 3-1 Improvement of the Jumbo viaduct alignment on B63 road which is shown schematically in Figure 3-2 EIA GSJ at Pont Fer / Jumbo / Dowlut Roundabouts 3-2 May 2017 M191/GSJ/3.1 Improvement to the existing 3 legs intersection at Jumbo Roundabout as shown in Figure 3-3 Improvement of the alignment of the ramp at Dowlut Roundabout as shown in Figure 3-4 A new link road from, Swami Baktivedanta Road (Sodnac Link Road) B94 to Phoenix-Beau Songes Road B130 as shown in Figure 3-3. Figure 3-1: Proposed Pont Fer Viaduct Figure 3-2: Proposed Jumbo Viaduct Figure 3-3: Proposed 3-leg Intersection at Figure 3-4: Alignment of Ramp at Dowlut Jumbo Roundabout EIA GSJ at Pont Fer / Jumbo / Dowlut Roundabouts 3-3 May 2017 M191/GSJ/3.1 Overall, the project is as shown schematically Figure 3-5. The context of the proposed project is shown in Drawing M191/GSJ/EV/LA/02. Figure 3-5: Overall Proposed Improvement. Through the proposed Road Decongestion Programme the RDA expects to meet, amongst others, the following objectives: To provide efficient and effective transport services in support of development, business, trade, tourism and production sectors of the economy To reduce vehicle operating costs, travel time costs and road maintenance costs To reduce traffic congestion on the existing motorways by: providing increased road capacity and bypass alternatives to Port Louis; responding to traffic growth by future expansion of road capacity; and implementation of suitable and effective traffic congestion management procedures To reduce traffic accidents and enhance road safety. 3.3 Proposed Works and Road Design The key components of the proposed works include the following: EIA GSJ at Pont Fer / Jumbo / Dowlut Roundabouts 3-4 May 2017 M191/GSJ/3.1 Improvement of entrance and exit for industrial area on Pont Fer Roundabout Improvement of Pont Fer viaduct alignment on M1 Motorway Improvement of the Jumbo viaduct alignment on B63 road Change of the existing Jumbo Roundabout to 3 legs intersection Improvement of alignment of the ramp at Dowlut Roundabout Diversion and protection of all affected utility services, cables, etc. Construction and installation of all required ancillary buildings, offices and road furniture Construction of additional lane at Pont Fer and extension of culvert at River Mesnil will entail the following: . Temporary diversion of existing river flow to proceed with construction works . Realignment of existing river to original alignment. The road design involves the following main fields, amongst others: Geometric design Pavement design Bridge Geotechnical engineering Traffic analysis. The following sections 3.4 to 3.7 have been extracted from the FEED Report produced by KEC in association with Cheil Engineering Co. Ltd. and Kyongdong Engineering .Co Ltd. 3.4 Geometric Design As a basic element of the road design, the road design standard should be based on various factors: function of roads, traffic and site conditions, geological and geotechnical conditions, social environmental and economic factors. According to the design standard stipulated in the Contract Agreement between RDA and KEC (signed on 25 Nov., 2016), all design fields will basically follow local standards and AASHTO standards. The Consultant will comply with the followings as reference standards in the order of priority listed below, unless otherwise specified. Local standards AASHTO Standard, 2011, AASHTO, USA(Design Standard for the Project) Design Manual for Road and Bridges Volume 6, 2015, British Standard, UK Road Design Standard, 2012, Ministry of Land, Infrastructure and Transport, Republic of Korea EIA GSJ at Pont Fer / Jumbo / Dowlut Roundabouts 3-5 May 2017 M191/GSJ/3.1 South African Pavement Engineering Manual Second Edition, 2014, - The South African National Road Agency Southern African Transport and Communications Commission,1998, - The division of Roads and Transport Technology. 3.4.1 Road Classifications According to the Road Traffic (Speed) Regulations 2011 of Mauritius, the roads in Mauritius are classified into four categories: Motorway, A roads, B roads, and Un-rated roads. Regarding the road classification for the project, the RDA informed that all RDP projects would normally consist of 'A Class' road. Based on this information, the project road sections to be newly constructed are classified as 'A road' while current classifications remain the same for the existing roads subject to upgrade. The road classifications for each section of the Grade Separated Junction at Pont Fer-Jumbo-Dowlut (GSJ) are as follows: Table 3-1 below shows road classification according to the AASHTO Manual. Table 3-1 - Road Classification on Project road Local AASHTO Project Road Classification Standard,2011 M1 Motorway Motorway Freeway A10 Road A road Arterial Grade Separated B63 Road B road Arterial Junction Sodnac Link B road Arterial Road(B94) 3.4.2 Design Speeds The Road Traffic (Speed) Regulations 2011 provided by the RDA defines the maximum speed ranges by road classification and vehicle type as follows: Motorway : 80 ~ 110 km/h A road : 60 ~ 80 km/h B road : 40 ~ 60 km/h. Considering operating speed limit on the A1 road, the design speed of the A1-M1 Link Road is decided as 60km/h. The adopted design speed of the existing roads to be improved in the Grade Separated Junctions at Pont Fer