In Tamil Nadu, there is a separate Highways Department (HD) which was established in April 1946 and renamed as Highways & Minor Ports Department (HMPD) on 30 October 2008. HMPD of Tamil Nadu is primarily responsible for construction and maintenance of roads including national highways, state highways and major district roads in Tamil Nadu.

Roads with traffic density less than 10,000 PCUs but more than 5,000 PCUs are designated as major district roads (MDR). MDRs provide linkage between production and marketing centres within a district. They also provide connections between district and taluk headquarters with the state highways and national highways. Construction and maintenance is carryout by the Highways Department for MDR along with state highways and ODR. These roads have a minimum width of 15 meters.

Lane wise distribution

Details of lane wise distribution of MDR roads in Tamil Nadu as of March 2013:

S. noDivision Single lane (in km)Intermediate lane (in km)Double lane (in km)Multi lane (in km)Total (in km) 1 Chennai City Roads 31.73 10.01 41.74 2 Tiruvallur 69.50 96.45 119.02 7.00 291.97 3 Chengalpattu 129.61 89.25 152.83 5.30 376.98 4 Vellore 97.80 55.60 60.65 12.65 226.70 5 Vaniyambadi 8.80 20.00 29.96 1.60 60.36 6 Thiruvannamalai 139.00 191.30 110.95 441.25 7 Villupuram 66.15 102.32 18.52 186.99 8 Kallakurichi 189.35 52.50 47.30 289.15 9 Cuddalore 162.72 158.61 73.78 0.40 395.50 10 Ariyalur 93.60 85.71 42.19 1.40 222.90 11 Trichy 165.31 112.65 55.52 2.50 335.98 12 Pudukottai 97.59 311.97 27.87 437.43 13 Thanjavur 182.20 214.18 47.73 444.10 14 Nagapattinam 81.01 201.71 14.85 1.20 298.76 15 Tiruvarur 124.00 92.95 13.40 230.35 16 Salem 212.57 152.67 238.94 16.73 620.90 17 Namakkal 10.50 191.64 69.94 1.95 274.04 18 Krishnagiri 28.31 153.09 109.20 2.76 293.36 19 Dharmapuri 73.70 117.03 87.91 278.64 20 Tiruppur 62.00 87.88 79.61 9.20 238.68 21 Dharapuram 91.12 130.79 47.45 269.36 22 Erode 62.00 86.82 103.13 3.06 255.00 23 Karur 113.72 218.68 75.20 407.60 24 Coimbatore 29.40 105.25 155.00 26.17 315.82 25 Pollachi 72.14 83.50 27.95 0.80 184.39 26 Gobi 31.30 98.20 75.47 2.24 207.20 27 Ooty 27.37 148.80 4.20 180.37 28 Madurai 176.30 68.00 306.25 1.60 552.14 29 Theni 6.18 90.85 129.03 226.05 30 Dindigul 284.93 328.29 144.50 0.97 758.69 31 Sivagangai 154.86 124.16 40.67 0.80 320.49 32 Ramanathapuram 144.98 141.36 40.80 327.14 33 Tirunelveli 107.82 60.44 54.21 0.00 222.47 34 Tenkasi 56.98 68.90 38.80 164.67 35 Thoothukudi 95.62 100.39 95.48 2.28 293.77 36 Virudhunagar 202.53 109.21 20.91 332.64 37 Nagercoil 55.38 76.20 104.62 236.20 38 Cheyyar 39 Perambalur Grand Total 3706.34 4527.33 2895.52 110.61 11239.79

List of MDRs List of major district roads in Tamil Nadu (as of March 2019).

MDR 1 to MDR 100

Road numberOSM relationName of roadDivisionLength (in km)Remarks MDR OSM Soolaimeni - Thervoy Kandigai Road Tiruvallur 4.80 MDR OSM Pattukkottai Bypass Road Thanjavur 7.40 MDR OSM Velankanni - Thiruthuraipoondi Road (Abandoned Section) Nagapattinam 1.057 KM 16/23 to KM 16/68, KM 22/015 to KM 22/399, KM 22/432 to KM 22/655. MDR OSM Rasipuram Bypass Road Namakkal 6.00 KM 2/8 to KM 8/8 MDR1 OSM Abulkalam Azad Road Tirunelveli 1.80 MDR5 OSM Aduthurai - South Thiruneelakudi Road Thanjavur 2.80 KM 10/4 to KM 13/2 MDR6 OSM Ayikudi - Nainaragaram Road Tenkasi 3.20 MDR7 OSM Akkur Railway Feeder Road Nagapattinam 0.80 MDR9 OSM Alagesapuram Road Tuticorin 1.32 MDR10 OSM Alampatti - Sedapatti Road Madurai 18.40 MDR11 OSM Alapakkam Railway Feeder Road Cuddalore 0.524 MDR12 OSM Allithurai - Thogaimalai Road Trichy, Karur 28.20 KM 5/4 to KM 33/6, road till KM 5/4 is part of another MDR MDR13 OSM Ambarampalayam - Anaimalai - Sethumadai Road Pollachi 16.00 MDR till KM 16/0, from there unclassified road MDR14 Ambasamudram - Alangulam Road 20.40 Upgraded as SH40B MDR16 OSM Ambasamudram Travellers Bungalow Road Tirunelveli 1.00 MDR18 OSM Ambur - Sathgur Road Vaniyambadi 1.80 Ambur town limit MDR21 OSM Ammapettai - Vaduvur Road Thanjavur, Tiruvarur 13.70 MDR22 OSM Anaimalai - Poolankinar Road Pollachi, Dharapuram 32.40 MDR23 OSM Anaimalai Loop Road Pollachi 7.80 MDR27 OSM Anjugramam Road Nagercoil 10.30 MDR28 OSM Anthiyur - Ammapettai Road Erode 17.40 MDR29 OSM Anthiyur - Athani Road Erode 9.20 MDR30 OSM Arachalur - Sivagiri - Thamaraipalayam Road Erode 20.60 MDR32 OSM Tiruvallur - Arakkonam Road Tiruvallur, Vellore 20.80 MDR34 OSM Arasalar New Bridge Approach Road Thanjavur 0.427 MDR35 OSM Aravakurichy - Chinnadharapuram Road Karur 10.03 MDR37 OSM Aravakurichy - Pungampadi Road Karur 6.60 MDR till 6/6, from Dindigul district border another MDR continues with origin from 6/4, overlapping between divisions. MDR38 Arisipallayam - Cherring Cross Road 1.20 KM 2/4 to KM 3/6, upgraded as SH218 MDR40 OSM Arni - Devikapuram Road Cheyyar 21.20 MDR41 OSM Arni - Ettivadi Road Cheyyar, Tiruvannamalai 17.70 MDR42 OSM Arni - Kalambur Road Tiruvannamalai 0.80 Extension to MDR41 (KM 9/6 to KM 10/4) MDR43 OSM Arni - Vandavasi Road Cheyyar 39.20 MDR44 OSM Arungunam Road Cuddalore 4.40 MDR45 Athiyuthu-Surandai road 12.00 Upgraded as SH39B MDR46 OSM Attaiyampatti - Masakkalipatti Road Salem, Namakkal 12.80 MDR48 OSM Avaniapuram - Thirupparankundram Road Madurai 4.80 MDR52 OSM Ayyampettai Railway Approach Road Thanjavur 1.60 MDR53 Bagalur - Berigai Road 12.00 Upgraded as SH17C MDR54 OSM Balamore Road Nagercoil 20.40 KM 17/2 to KM 37/6 MDR55 OSM Bauxite Mines Road Salem 2.00 MDR57 OSM Bhavani - Kavandapady Road Gopichettipalayam 13.60 MDR58 OSM Bodi - Kurangani Road Theni 10.00 KM 6/0 to KM 16/0, till KM 6/0 it is NH MDR59 OSM Brahmin Burning Ghat - Vijayapuram Regulator Road Tiruvarur 0.60 MDR62 OSM Thindal - Periyasemur Link Road via Villarasampatti Bypass Erode 8.40 MDR65 OSM Chennai - Kovalam - Mamallapuram Road Chengalpattu 5.60 KM 35/2 - KM 40/0 and KM 57/6 - KM 58/4 MDR66 OSM Chennai - Ponnerikarai - Kanchipuram Road Chengalpattu 4.50 KM 70/4 - KM 74/9 MDR70 OSM Chennimalai - Arachalur - Kodumudi Road Erode 13.60 MDR71 OSM Chennimalai - Uthukuli Road Erode, Tiruppur 18.20 MDR73 OSM Chetinad Railway Feeder Road Sivagangai 2.781 MDR75 OSM Cheyyar Bypass Road Cheyyar 0.60 MDR78 Chinnamanur - Seepalakottai Road 8.80 Upgraded as SH227 MDR80 OSM Chunampet Road Villupuram 3.00 MDR81 OSM Coimbatore - Siruvani Road Coimbatore 29.80 MDR till KM 29/8, from there unclassified road MDR83 OSM College Campus Road - Karaikudi Railway Station Road Sivagangai 1.20 MDR84 OSM Construction Road Tuticorin 2.80 MDR86 OSM Coonoor - Kundha Road Udhagai 26.80 MDR from KM 3/2 to KM 30/3, till KM 3/2 it is NH MDR87 OSM Courtallam - Five Falls Road Tenkasi 4.00 MDR88 OSM Courtallam - Mathalamparai Road Tenkasi 7.40 MDR89 OSM Cuddalore - Pallineliyanur Road Cuddalore, Villupuram 17.50 MDR from KM 2/8 till KM 4/3 and from KM 7/6 till KM 23/6. KM 4/3 till KM 7/6 is under Puducherry UT. MDR90 OSM Cumbam - Cumbammettu Road Theni 12.80 at KM 12/8 it is Kerala state border, road joins with SH there MDR91 OSM Denkanikottai - Kelamangalam - Uddanapalli Road Krishnagiri 21.20 MDR93 OSM Devipattinam - Pottagavayal - Nainarkoil Road Ramanathapuram 27.20 KM 0/0 to KM 12/8 and KM 15/8 to KM 30/2, in between it is ODR MDR94 OSM Dhali - Komaralingam Road Dharapuram 16.80 MDR95 OSM Dharapuram Bypass Road Dharapuram 0.40 KM 3/8 to KM 4/2, till KM 3/8 it is SH MDR96 OSM Dharapuram - Pollachi Road Dharapuram 1.00 KM 0/6 to KM 1/6 MDR100 OSM Dharmapuri - Papparapatti Road Dharmapuri 13.20

MDR 101 to MDR 200