appendix i-traffic assessment report.pdf

8/13/2019 Appendix I-Traffic Assessment Report.pdf

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Transport Impact Assessment

Report Prepared for

Gulf Power Ltd.

NEMA Reference No. NEMA/PR/5/2/6972

Report No. 201004-EIA-004

July 2010

Prepared By: Eng. Mordecai Kere Omenda

Maxcad Consulting Engineers

P. O. Box 40482 80100

Mombasa, Kenya

Your Health, Safety & Environment Partner


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ESIA Study of the Proposed IPP Power Plant, Mombasa Road, Athi River, Kenya

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1 Introduction

Maxcad Consulting Engineers was commissioned by Nutek Solutions Ltd.to undertake a traffic/transportation impact study as part of theenvironment and social impact assessment for the proposed IndependentPower Plant development to be located near Athi River off the Mombasa

Nairobi highway (A109), Athi River, in the Republic of Kenya.This report contains a description of the current status of transportenvironment and infrastructure along the A109, the transport/trafficimpact during the construction and operation of the proposed Power Station and access road alternative evaluation. The proposed power plant is to be situated off Mombasa-Nairobi Road at Athi River, amunicipal council authority with a population of about 65,000 inhabitants.

1.1 Existing status or Condition

The following section summarizes the present situation as it relates totraffic/transportation for the development of the proposed power plant.

The A109 international trunk road links the portal city of Mombasa toNairobi, the Kenyan hinterland and neighboring countries like theDemocratic Republic of Congo, Uganda, Rwanda and Burundi. Trafficvolumes passing through the highway were gotten from the Ministry of Roads. Traffic on the A109 was studied on the basis of historical trafficdata obtained from the Ministry of Roads and traffic surveys conductedby an independent consultant in 2001. Additional traffic surveys wereundertaken by the consultant in August 2003 and formed the basis of predicting present traffic characteristics.

The latest road traffic on the A109 traffic counts that could be obtained

were 24hour (07:00am to 7:00am) at the A104/A109 junction. Sevenconsecutive day counts were carried out to ensure better accuracy in thecalculation of Average Daily Traffic (ADT).

Table 1: Traffic Count Lo cations

Point Location

4 main locations

1 Junction of A109/C97 at Machakos turn-off

2 Junction of A109/A104 at Namanga turn-off

3 Weighbridge Station (Km. 5.5 from Embakasi)

4 End of dual carriageway at Embakasi

2 minor locations

5 Junction of A109/D527

6 Junction of A109/D519


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Throughout the study, vehicle classes contained in table 2 below arerecognized. While they are based upon the Ministrys system of classification for road counts, an extra category of vehicles has beenadded in the LGV class, namely matatus . This class has become broader over the years as matatus have come to include the 3-ton light trucks thatare built with a bus body. The class is usually combined with LGV into a

heterogeneous mix of vehicles from 0.75 3 metric ton carrying capacity.These are often counted separately in view of their crucial role in publictransport.

Table 2: Vehicle classification system used by th e Minis try of Roads

Vehicle Class Description

Cars (C) Sedans, 4x4, and station wagons with up to 9 passenger seats.

Light Goods Vehicle(LGV)

Pick-ups, vans, and other goods vehicles of up to 1.5tons carrying capacity (goods vehicles of less than 1,524kg unladen weight).

Matatus (M) Passenger service vehicles of 9 25 passengers.

Medium GoodsVehicles (MGV)

Two-axle trucks, including some light tankers (over 1,524kg unladen weight).

Heavy GoodsVehicles (HGV)

Multi-axle trucks and truck-trailer combinations. This isalso a heterogeneous category as there is a multiplicityof configurations. In some studies oil tankers arecounted separately in view of the notorious problem of exceeding axle weights and in order to determinecompetition from the oil pipeline (see later). A separatesub-category was adopted for oil tankers, which are all

HGV carrying bulk liquids.Bus (B) Vehicles with seating capacity exceeding 25 seats.

Oil Tankers (OT) All goods vehicles carrying petroleum products.

1.2 Present Traffic Characteristics

1.2.1 Traffic Composition

Data from all census sites on road A104/A109 for through traffic on thecurrent composition of vehicle types using the road for each class of vehicle are presented in the Table below.

Traffic Compositi on (%)

C V M LG M MG HG HG B

Mombasa bound Carriageway

Embakasi -Weighbridgestation

31.4 1.8 18.5 20.1 1.5 8.3 2.2 10.7 5.5

Weighbridgestation - Namanga

32.4 1.3 20.7 16.6 1.5 8.6 2.1 10.8 6.0


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Traffic Compositi on (%)

C V M LG M MG HG HG B

Junction

Namanga unction- Lukenya junction 23.9 0.4 15.4 16.8 0.5 12.9 2.1 19.9 8.1

Lukenya unction -Machakos Turnoff 22.7 0.4 17.5 16.6 0.3 12.4 2.3 19.0 8.8

Road Section Average 27.6 36.5 11.5 17.3 7.1

Nairob i bound Carriageway

Embakasi Weighbridge Stn. 29.1 1.6 18.9 20.4 0.5 10.3 1.6 12.6 5.0

Weighbridge Stn.- Namanga Jctn. 30.7 1.5 20.4 17.8 0.6 9.2 1.6 13.1 5.1

Namanga Jctn.-Lukenya Jctn. 23.5 0.7 15.6 15.7 0.5 16.4 2.4 17.5 7.7

Lukenya Jctn. -Machakos Turnoff 21.9 0.5 16.5 15.7 0.5 12.6 2.9 21.3 8.1

Road Section Average 26.3 36.3 12.7 18.3 6.4

The results indicate that the composition of vehicles on all census sitesfor through traffic varied but the general pattern is that the predominanttraffic class for the road is the Passenger Cars category with ratios of 22

32%. When the Light Goods Vehicles are combined (LGV = V + M +LGO), this category becomes the predominant traffic class with ratios of 32 41%.

From the above Table, it can be seen that the percentage for the HeavyGoods Vehicles category increases from 13% to 24%.

1.2.2 ADT and AADT for Embakasi Machakos turn-off

With reference to the consultants report, the seven-day count at eachstation was converted to 24-hour counts by multiplying the 12-hour counts by a night-count factor. The 24-hour counts were then divided bythe number of count days to get the Average Daily Traffic (ADT). The

ADT figures were then multiplied by the mean seasonal adjustment factor of 1.00 for weeks 31 and 32 in which the counts were carried out, asgiven by the MoR, to obtain the AADT.

Table 3: Summarized 2003 AADT values

2003 AADT Link Volumes

C LGV MGV HTG HTO B TOTAL

V M LGO MGT MGO


Embakasi-Weighbridge 1996 112 1175 1275 93 528 138 680 357 6354


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2003 AADT Link Volumes

C LGV MGV HTG HTO B TOTAL

V M LGO MGT MGO

Weighbridge-NamangaJctn.

1904 74 1217 972 90 506 126 637 346 5872

NamangaJctn.-Lukenya

741 13 477 520 15 400 64 619 254 3103

Lukenya -MachakosT/O

640 10 492 468 9 350 65 535 250 2819



Weighbridge-Namanga

Jctn.

1870 89 1246 1083 34 562 100 801 313 6098

NamangaJctn.-Lukenya(D527)

698 21 464 468 14 487 70 521 233 2976

Lukenya-MachakosT/O

625 13 473 449 13 360 83 609 234 2859

1.2.3 Traffic Forecasts in AADT

From the design report for project road A109, Year 2007 was assumed

as the first year after construction of the project road, i.e. the base year.By applying the established growth rates to the 2003 AADT, and takinginto account traffic generation, forecast traffic is shown in the Table belowfor the 15 th year after opening the road to traffic. The Table below isbased on the forecast medium (expected) growth rates.

Table 4: Projected Traffic Volumes (AADT) for year 2021 Medium Growth Rates

Link C V M LGO MGT MGO HGT HGO B TOTAL


Embakasi-

Weighbridge3704 235 3383 3643 72 1414 252 2041 591 15334


3368 190 3143 2732 66 1116 229 1837 512 13193

NamangaJctn.-Lukenya ctn.(D527)

1257 45 1170 1181 27 944 161 1195 381 6361

Lukenya 949 23 985 935 21 575 181 1330 454 5452


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Link C V M LGO MGT MGO HGT HGO B TOTAL

Machakos




3429 158 3070 2452 175 1005 289 1461 566 12604

NamangaJctn.-Lukenya

1334 28 1203 1312 29 776 147 1420 416 6664

LukenyaMachakos 971 18 1024 974 14 559 142 1169 485 5356

1.2.4 Projected Traffic Loading

Present traffic loadings were computed by applying the equivalence load

factors to the present (2003) traffic volumes. Projected traffic loadingswere then computed by applying the estimated growth rates to thepresent traffic loading. The results for the 15-year analysis period to year 2021 at medium (expected) growth rates are shown in the Table below.

LinkCumulative Equivalent Standard Axles Year 2021 at Medium GrowthRate TRAFFIC

CLASSMGT MGO HGT HGO B TOTAL


EmbakasiWeighbridge(1x10 6)

0.8 10.3 16.5 49.6 6.5 83.8

T0

Weighbridge NamangaJunction(1x10 6)

0.7 11.0 11.9 58.5 5.7 87.8

NamangaJunction Lukenya(1x10 6)

0.3 7.9 9.2 44.7 5.0 67.1

LukenyaMachakosTurnoff (1x10 6)

0.2 6.7 9.4 42.3 4.4 63.0

Mombasa bound CarriagewayEmbakasiWeighbridge(1x10 6)

0.2 4.1 1.6 22.8 4.1 32.9

T1Weighbridge NamangaJunction(1x10 6)

0.2 2.9 1.9 16.3 4.0 25.3

NamangaJunction

0.1 2.1 1.0 14.9 2.9 21.0 T2


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LinkCumulative Equivalent Standard Axles Year 2021 at Medium GrowthRate TRAFFIC

CLASSMGT MGO HGT HGO B TOTAL

Lukenya(1x10 6)

LukenyaMachakosTurnoff (1x10 6)

0.1 1.9 1.0 12.8 2.9 18.7

For the Nairobi bound carriageway, the cumulative standard axlesrange between 57.276.0, 63.083.8 and 69.797.0 million for low,medium and high traffic growth rates respectively. The cumulativestandard axles exceed the limits of traffic class T1 hence the designtraffic loading for the entire length of the carriageway falls under trafficclass T0 (over 60 million ESA).

For the Mombasa bound carriageway, the corresponding cumulative

standard axles range between 17.029.8, 18.732.9 and 20.636.4million for low, medium and high traffic growth rates respectively for the15-year period.

The dual carriageway shall end at Km. 12+500 just after the NamangaJunction. For the section between Km. 0+000 and this location, theMombasa bound carriageway shall be constructed to design trafficclass T1 whilst the Nairobi bound carriageway shall be constructed todesign traffic class T0. Beyond this location where the two carriagewaysmerge, the single carriageway shall be constructed to design traffic classT0.

1.3 Description of Road Infrastructure

The proposed IPP is located about 30km from Makutano junction(junction to Machakos) and about 3km from Athi River town. The road isunder construction and currently the contractor is dumping cut to spoilmaterial along the farm near to the boundary to the road reserve. Theresidential township of Kitengela located on an east-west alignedbituminous road, Embakasi located on a southern-west alignedbituminous road and township of Makutano on A109 bituminous highway.

A map highlighting these roads and other transport infrastructure isshown in Appendix W., Figure 4.

1.4 Location of Employee ResidencesFrom the existing travel patterns observed in relation to other factories in

Athi River, a clear indication that the major source of employees or their residential areas shall be located in Kitengela, Makutano, Mavoko,Embakasi, Mlolongo and as far as Machakos. This is not expected tochange for the operation of the proposed new power station.


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1.5 Other Transport Infrastructure

There is a multi-products white oils pipeline running parallel to A109 road,but outside the road reserve.

1.6 Assumptions for Traffic/Transport Impact

1.6.1 Proposed Power Station

IPP Power Station output is approximately 84 MW.The proposed new power station will require at least one major access road for employees from A109 road to the site.The number of employees and vehicles generated/attracted to theproposed IPP Power Station will be based on the proportion of thepower station output. As a result a significant workforce would need tobe housed most probably in the expansion of the present residentialareas of Athi River, Kitengela or Makutano.IPP Power Station will be cited more or less centrally on the 4 hectare

piece of land.

1.6.2 Fuel Supply

The HFO supply from Mombasa is infinite in magnitude for the designlife of the proposed power station.Fuel oil supply transport will be undertaken in oil tankers via A109road from Mombasa on Nairobi bound, the estimated number of trucks at normal and peak operating conditions is proposed to be 10 -15 tank trucks in number per day.

1.7 Traffic/Transport Impacts

1.7.1 Access Road/ Provincial Road Re-alignment Alternatives

The present National highway Road (A109) to Nairobi/Mombasa passesa few meters away from the power plant site. The Road (A109) wouldhave to be realigned and redesigned to accommodate the vehicles whichshall be turning to and from the power station with more emphasis onheavy traffic during construction and operation.

The Kenya National Highways Authority would have to be consulted torealign the road and provide the design for access junction to theproposed IPP station.

1.7.2 Transport of Components during Construction

During the construction phase, each of the seven MSD engines willrequire to be transported from Mombasa to the power plant site. Thefrequency of delivery would be no more than 1 every three months. Thiswould require abnormal load transport and the application for the permitto do so is needs to be planned well in advance.


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Other applications shall involve the following bodies:

Kenya Power and Lighting Co. Ltd. to disconnect or cut off or evaluatetheir electrical wiring cables that would obstruct the Engines beinghauled. The evaluation and approvals shall cover the entire route fromKenya Ports Authority to Athi River

Kenya Ports Authority Berths can only carry certain loadings spreadover the berthing structures. Assessments and approvals shall besought from Kenya Ports authority as to adequacy for offloading asusually heavy engines on to the berths prior to transportation to AthiRiver.

Evaluation of rail over road bridges near Mombasa in case the optionof using Makupa causeway, Mombasa town part of A 109 becomesthe approved option if the bridge at Kipevu near Changamwe which isbuilt of masonry with concrete decking topping is found to exhibitinadequate load carrying capacity.

1.7.2.1 Abnormal Load Permit Application

The critical part of the Abnormal Load Route Permit application is thesurvey of the prospective route by a qualified structural Engineer whoneeds to examine all the bridges/overpasses/underpasses and issue acertificate of compliance for the particular vehicle type/width/length andheight.

It is estimated that the whole survey and Application procedure maytake three to four months to complete, and this would have to bescheduled in the construction programme of the Athi River IPP Power Station. Although the tonnage is significant the low frequency of thetrips means that the traffic loading impact is negligible. Close to the

construction site, turning radii of 60m is required for the large superlinkloads.

The transport of components impact is slight, the extent is regional, theduration is very short term, it will definitely occur, its significance is low,and the degree of certainty is definite.

1.7.3 Construction Traffic

This traffic relates directly to the traffic expected during the constructionof the proposed Power Station itself, which is expected to take place over a period of 12 months. It is anticipated and estimated that the number of construction employees to/from the construction site will be of the order of 600 per day. There is a possibility that a temporary construction campcould be established on the site, to accommodate constructionemployees. These employees would not need to use the external roadsto access the site. It is conservatively assumed that the balance of theconstruction workers would typically be transported to site by bus. Invehicular terms 12 buses are required and 42 cars are expected to begenerated assuming an average occupancy of 1.2 per car. Of this dailyconstruction employee traffic 75% is conservatively assumed to arrive inthe a.m. peak hour and depart in the p.m. peak hour.


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The magnitude and exact nature of heavy vehicle construction traffic isvery difficult to determine. The sources of construction materials, supplyof material components and the construction programme all influence thenature and frequency of road-based vehicle transport to/from the site.The source of construction material would mainly be Ruai. The rawmaterials for the on-site Cement plant will be from East Africa Portland

Cement, Athi River. The heavy vehicle construction traffic is assumed toamount to 10 trucks per day.

50% of the trucks are expected to arrive during the A.M peak hour anddepart in the P.M. peak.

The impact on pavement loading to the surrounding roads may, however,be more significant. Assuming the 10 truckloads per day which are fullyloaded inbound (42 tonnes per truck) and empty outbound (2.8 tonnesper truck) translates to 450 tonnes per day along Road A109.

This represents a percentage proportion. The accumulative additionalaxle loading over a sustained operational period is relatively significant.The overall impact of the construction traffic during the constructionperiod translates to advancing the need for pavement rehabilitation andimprovement. This situation is the worst-case at point of turning to theproposed power plant from the main road.

The effect on pavement loading and subsequent advance of anyrehabilitation programme should be mitigated after completion of construction. Such mitigation and associated costs would need to bediscussed between IPP management and the Kenya National HighwaysRoads Authority.

The construction traffic impact is moderately severe, the extent islocalized, the duration is long term, it will definitely occur, its significanceis moderate, and the degree of certainty is probable.

1.7.4 Transport of Employees (Operational Traffic)

The additional traffic generated in transporting employees from their residences to work at the IPP Power Station will be expected from major residential areas.

In broad terms the nature and magnitude of traffic to the proposed AthiRiver Independent Power Plant Station is expected to slightly increasewith the employee traffic being directed to the location of the newproposed power station site.

The effect on pavement loading and subsequent advance of anyrehabilitation programme should be mitigated. Such mitigation andassociated costs would need to be discussed between the Proponent andthe Kenya National Highways Roads Authority. Agreement would need tobe reached regarding mandates and responsibility for the roadrehabilitation sections of the junction to the IPP on road A109. Thenegotiation should however also consider the economic growth, jobopportunities and increased local economy created by the proposedPower Station.


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The operational traffic impact is moderately severe, the extent islocalized, the duration is long term, it will definitely occur, its significanceis high, and the degree of certainty is definite.

1.7.5 Fuel Supply Transportation

The fuel supply oil tankers are required to serve the proposed Power Station from pipeline oil pump station located in Mombasa to the Power Station by road using the A109, this is estimated at 10 15 HFO oiltankers per day carrying a maximum of 28m 3 (25 metric tons) of fueldaily.

Reviewing the projected Traffic Volumes for year 2021 on base trafficcensus of year 2003, it is concluded that the projected this additionaltraffic volume on A109 Mombasa- Athi River falls within the traffic growthand should not be considered outside the traffic distribution pattern for highway loading pattern.

However, there are other Environmental impacts that shall be of concern.

These include Possible increase in dangers due to accidents, oil spills and

associated dangers

Increased traffic volumes affecting the junction off A109,which willconsiderably decrease through way traffic capacity even with designof deceleration and acceleration lanes

1.8 Conclusions

The provincial road re-alignment impact is moderately severe, theextent is regional, the duration is permanent, it will definitely occur, its

significance is moderate , and the degree of certainty is definite.The transport of components impact is slight, the extent is regional,the duration is very short term, it will definitely occur, its significance islow, and the degree of certainty is definite.The construction traffic impact is moderately severe, the extent islocalised, the duration is short term, it will definitely occur, itssignificance is moderate, and the degree of certainty is probable.The operational traffic impact is moderately severe, the extent islocalised, the duration is long term, it will definitely occur, itssignificance is high, and the degree of certainty is definite.


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1.9 Pictorial Illustrations

PICTURE NUMBER 1

PICTURE SHOWING SECTION OF A109 LOOKING TOWARDSNAIROBI

PICTURE SHOWING SECTION OF A109 AT THE PROPOSEDJUNCTION WHERE THE POWER PLANT ACCESS ROAD ISPROPOSED


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1.10 Recommendations

It is recommended that the effect on pavement loading and subsequentadvance of any road rehabilitation program should be mitigated after completion of construction. Such mitigation and associated costs wouldneed to be discussed between and the Kenya National Highways

Roads Authority. Agreement would need to be reached regardingmandates and responsibility for the roads rehabilitation programme for the point of turnoff to the proposed IPP station.

A109 is an international trunk road and the Government policy on suchclassified roads is that there ought not to be at grade interchanges.

However, as it is recognized that traffic supplying fuel to ther plant isenvisaged to branch off A109, there shall be need for design approvalsfor adequate deceleration lane for traffic towards the IPP off NairobiBound lane and acceleration lane, off Nairobi Bound lane toaccommodate the lorries that have off loaded fuels.

Depending on economy of transportation planning, if the option of immediate return for fuel re0filling has to be immediately after dischargingat the IPP, then there shall be requirement to accommodate this suddensurge in traffic on one of the Grade separated interchanges within AthiRiver, which shall be more of a management problem as to efficiency,safety and risk reduction in the entire operation process.

The design procedures for horizontal and vertical alignments shall followthe principles or proposals contained in Road designers manual part 3,part of which are replicated hereunder for ease of reference are some of the standards that shall be discussed and approvals sought from theNational Highways Authority.

Below are some of the proposals contained in the Road designersmanual, that may be adopted by the design engineers while pursuingapprovals for connections to a109 from the National Highways authority.


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TYPICAL AT-GRADE JUNCTIONS DESIGN IN ACCORDANCE WITHKENYAN ROAD DESIGNERS MANUAL


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THIS OPTION FOR EXIT OFF A109 AT GRADE JUNCTION FROMMOMBASA TRIP AFTER FUELLING PROPOSED EXITDECELERATION LANE, THE SAME SHALL BE MIRROR REPLICATEDFOR ACCELERATION LANE TO A109


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THIS OPTION FOR RETURN TO MOMBASA TRIP FOR RE-FUELLINGWITHIN THE EXISTING AT GRADE INTERCHANGES


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THIS OPTION FOR RETURN TO MOMBASA TRIP FOR RE-FUELLINGWITHIN THE EXISTING AT GRADE INTERCHANGES

appendix i-traffic assessment report.pdf

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