Home‎ > ‎Countries‎ > ‎


Area code 975 Common abbreviation BHT Last updated 23-7-2017
Road class Syntax explanation Administrative subordination Sub classes Zones System Remarks
Asian highway AH48 Asia See Asia
National Highway {P}NH{1}[0-9];SL[1-4] national Primary sequential
Dzongkhag Road [DF]R[0-9]<2> national
General description:
Three different numbering systems appear on National Highways: PNH, NH and SL. PNH seems to be new and almost never appear on signs. The main east-west route is the SL2, also known as NH2 or PNH1. The highway from Thimphu to Phuentsholing used to be designated SL2 but since 2009 only its Asian Highway number 48 appears. Overview:
Route PNH number Former number Old number
Thimphu - Trashigang PNH1 SL2 NH2
Thimphu - Phuentsholing PNH2 AH48 SL2
Wangdue Phodrang - Damphu PNH5 SL4
Trongsa - Gelephu PNH4 NH4
Trashigang - Samdrup Jongkhar PNH3 none
Dzongkhag Roads are less important and sometimes appear with just 'DR'. They used to be Feeder Roads.
There are lower classes like Farm Roads, Thromde Roads and Access Roads but no numbering is known for these.
Road signs: Green with white text, red with yellow text on old signs. Until around 2013, road numbers only appeared on km stones with distances. Many variants appear: PNH, NH, SL, DR (Dzongkhag Road or District Road) and FR (Feeder Road or Farm Road), SNH without digits, DR without digits.
History: Bhutan joined the Asian Highway project in 2002, though the number only started appearing on signs in 2008 or 2009. Road classification was changed in 2009, see Road Guidelines and Road classification in Bhutan. Numbers 6 - 11 were introduced around 2016.
Sources and links: various websites

    Official sites:
  1. Road Safety and Transport Authority
  2. Road Act of Bhutan 2013
  3. English Road Guidelines

  4. Other links:
  5. List of highways without numbers
  6. Data collection survey on road connectivity in the Kingdom of Bhutan JICA
  7. Road classification in Bhutan Robert Bartlett
  8. Bhutan started numbering highways 2016
  9. Km stone with AH number by Brian McMorrow

  10. Other pages within this site:
  11. Asia
Marcel Monterie