Feasibility Study Report Mizoram State Roads Project –II Project Preparation Consultancy Services for Mizoram State Roads II Project (MSRP II) PPC Package I Phase-I: Junction NH-44A- Chungtlang-Darlung-Buarpui Chapter 5. Description of Alignment Alternatives 5.1 RECONNAISSANCE REPORT OF THE EXISTING CORRIDOR The existing project road is replete with short and sharp curves, series of S curves and some broken back curves. A maximum of 8 to 10% super elevation has been observed at the hair-pin bends where the existing bituminous surface is in fair condition, whereas for the gravel sections hardly any camber has been observed. There are also a number of sharp curves having inadequate sight distances. The speed of travel on the project corridor ranges from 10 to 25 kmph at most of the sections. Preliminary reconnaissance survey reveals that the project road that passes through villages and settlement areas which are generally located at the hill tops / ridges; therefore steep vertical up and down gradients areas are typical characteristics of the vertical geometry. The travel speeds are restricted generally due to the sharp curves, very steep grades and poor pavement condition. The following is the list of identified villages along the exist road with details of observed GPS coordinates and an approximate chainage from the start point of the project road: Table 5-1: Location of Villages Sl no Km Easting Northing Village Name 1 0 459458 2632140 Start of New Alignment at NH 44A Junction near Langte village 2 20 456497 2618391 End of New Alignment near Chungtlang village 3 27 458662 2614580 W Lungdar village 4 36 459399 2609126 Hreichuk village 5 43 456740 2605578 Kanghmun village 6 55 457979 2596647 Bawlte village 7 59 458917 2594640 Darlung village 8 61 459079 2593594 South Sabual village 9 78 462589 2584145 South Khawlek village 10 85 463501 2578918 New Khawlek village 11 92 464850 2573585 Buarpui village A strip chart showing the existing road with the village / settlement locations is projected as follows: Figure 5-1 5-1 Feasibility Study Report Mizoram State Roads Project –II Project Preparation Consultancy Services for Mizoram State Roads II Project (MSRP II) PPC Package I Phase-I: Junction NH-44A- Chungtlang-Darlung-Buarpui The existing corridor was traversed by the consultants from Km 20 to Km 95 (since from Km 0 to Km 20 there is no existing corridor) and the existing road profile and the existing gradients were mapped by the Consultants. The existing profile of the road is as follows: Figure 5-2 As inferred from the profile diagram that the proposed new alignment connects the existing road near Chungtlang village at Km 20 at an elevation of 897m after which the exiting road climbs steeply to village of W Lungdar which is located at the highest point where the elevation reaches 1262m. Again there is a marked fall in the existing alignment till the Hreichuk village located at Km 36 and having an elevation of 880m after which the existing road again climbs up to connect Kanghmun village at Km 43 at an elevation of 970m. Again there is a marked fall observed from Km 60 to Km 64 near Darlung and South Sabual village where the elevation drops from 955m to 709m within a distance of 4.5 kilometers. The remaining parts of the corridor shows the similar nature which is marked by sudden rise and fall in gradients. A summary of the relative elevations along the project corridor as recorded by the hand held GPS observed by the Consultant’s during site reconnaissance survey is given in Appendix 5.1 of Volume 2. The Consultant also mapped the gradients of existing corridor and the observation is as follows: Figure 5-3 The existing grade is mapped with respect to a limit line of 5% ruling grade. It is inferred that from Km 20 to Km 30 there is a predominant tendency of steep grades exceeding the ruling value for 5-2 Feasibility Study Report Mizoram State Roads Project –II Project Preparation Consultancy Services for Mizoram State Roads II Project (MSRP II) PPC Package I Phase-I: Junction NH-44A- Chungtlang-Darlung-Buarpui mountainous terrain at most of the mapped sections. Also from Km 55 to Km 68 there is considerable length which shows steep grades. Similarly the same is observed from Km 72 to Km 77 and from Km 86 to the end of the corridor. There are few locations like at Km 36, Km 42 and Km 48, where steep grades are observed but at short stretches. 5.2 FINALIZATION OF THE REALIGNMENT OPTIONS This section primarily focus on the selection of preferred route of the project corridor as mandated in the ToR and the purpose of the Route Selection Alternatives is to present Client (MPWD) and the other stake holders with possible alternate routes for a project road, together with an evaluation of each in technical, environmental and social terms. 5.2.1 Finalization of the start point of the Project Corridor On analysing the various connectivity options from NH 44A junction to the project corridor, the consultants found out the major two alternatives. The alternatives are as follows: 1. Option 1 – NH 44A Junction - Rawpuichhip – Chungtlang: The route starts on NH 44A and traverses nearly 26.8 Km along the existing NH upto the junction to ODR at the village of Rawpuichhip. From the junction the route option traverses along the ODR for a length of 20.4 Km and passes through the villages of Tuahzawl, Rulpuihlim and finally connects the project corridor at the Chungtlang village. 2. Option 2 – NH 44A Junction – Lengte – Chungtlang: The route was to start at the Junction point with NH 44A and follow PMGSY road to the village of Lengte. After traversing a length of 5 Km along the existing road, towards Lengte village, the Consultants assessed that a shortest route can be proposed which will be new alignment in between the take off point before the Lengte village and end of the Chungtlang village connecting the project corridor. The length of the proposed new alignment will be 20 Km. A key map showing all the alternatives are shown below: Start Point of Option-2: Consultant came to know by the PWD NH wing that there is a proposal of the realignment of the existing NH 44A and an upgradation (to NH standards) of the existing PMGSY road to Lengte which will serve as a shortest connectivity to the existing and re-aligned NH 44A with Aizawl bypassing Lengpui. The Consultant discussed this fact with the Client and other stake holders and finalised the starting point of the project corridor at a junction to the proposed upgraded PMGSY road. 5-3 Feasibility Study Report Mizoram State Roads Project –II Project Preparation Consultancy Services for Mizoram State Roads II Project (MSRP II) PPC Package I Phase-I: Junction NH-44A- Chungtlang-Darlung-Buarpui A – Junction on NH 44A. B – Existing PMGSY road to Lengte village. (Distance between A to B is 5 Km) C – Joining to project corridor after Chungtlang village. (Distance between B and C is 20 Km and D and C is 20.4 Km) D – Junction of NH 44A and ODR at Rawpuichhip village (Distance between A and D is 26.8 Km) Figure 5-4: Options for the connection between NH 44A and Chungtlang 5-4 Feasibility Study Report Mizoram State Roads Project –II Project Preparation Consultancy Services for Mizoram State Roads II Project (MSRP II) PPC Package I Phase-I: Junction NH-44A- Chungtlang-Darlung-Buarpui The Consultant reviewed the various options for the best possible alignment that will connect the NH 44A to the Project Corridor at Chungtlang village. The review was preliminarily based on the geometric features of the existing roads and the possible extent to which it can be upgraded to the desired standards. For the first option, it was observed that the portion of NH 44A (26.8 Km in length) is in fair condition with some of the portions of the section of road is under upgradation by the NH wing. The remaining portion of the NH can be rehabilitated by improvement of sharp curves (about 106 nos of curves having radius less than 30m and some of the hairpin bends) and 35% of the total length having gradients more than 5 to 6%. The remaining length which traverses along the ODR for a length of 20.4 Km will involve major realignments for its upgradation to the desired standards. There are about 268 nos of sharp curves including the hairpin bends having radius less than 30m and 62% of the corridor have gradients more than 5%. On further investigation of the second option, the Analysis of engineering, social and environmental criteria has been carried out for Option-1 and Option-2 and those are summarized Table 5-8 below: Table 5-2: Quantitative Comparison of Option-1 and Option-2 Particulars Option-1 Option-2 26.8+20.4=47.2 20 1. Length (km) 26.8 on NH and 20.4 on ODR New Alignment (i) existing road (km) 47.2 - (ii) new alignment - 20 2. Land Use (Length in m) - - (i) Agricultural/Jhum 18600 7080 (ii) Open Forests/ 16940 10470 Vegetation/Bamboo Forests (iii) Moderately Dense Forests 3000 2300 (iv) Stream/Water Body 160 150 (v) Residential/Commercial 8500 Nil 3. Structures affected 150 4. Affected social amenities - (estimated) (i) Urinals 7 Nil (ii) Water points 5 Nil 4. Land to be acquired (ha) 87.2 48 ha 5. Land slide proneness Medium Low to medium 5-5 Feasibility Study Report Mizoram State Roads Project –II Project Preparation Consultancy Services for Mizoram State Roads II Project (MSRP II) PPC Package I Phase-I: Junction NH-44A- Chungtlang-Darlung-Buarpui 6.