| Status | Road | Name | District | Length | Lighting | Alternative Route |
 | E6 | Kobbskaret | Nordland | 4457m | ? | Go via the Fv 613. |
| 555 | Kolltveit | Hordaland | 1070m | ? | Go around the tunnel. |
| E6 | Korgen | Nordland | 8600m | | Road 'Europaveien' over the montain. |
| 38 | Kragerøtunnelen | Telemark | 500m | ? | Go via the local road. |
| 863 | Kvalsundtunnelen | Nordland | ? | ? | ? |
| 609 | Kvernberg | Sogn og Fjordane | 779m | ? | Go around the tunnel. |
| E7 | Kvernhushaug | Hordaland | 542m | ? | Go around the tunnel (summer only). |
![]() | 331 | Kvitaskreda? | Sogn og Fjordane | @220m | None. | |
| E134 | Langfoss | Hordaland | 726m | ? | Go around the tunnel. |
 | E16 | Langhelle | Hordaland | 926 m | Yes | The track that follows the disused railway line nearer the shore has unlit tunnels with a bad surface where you will have to push your bike. You can also take the train from Vaksdal to Trengereid. |
| 862 | Langnes | Nordland | @1740m | ? | Go over the hill by using the Langnesvegen. |
| E18 | Larviksporten | Vestfold | 95m | ? | Go via the Rv 40 and Rv 303. |
| 502 | Lauåsen | Rogaland | 232m | ? | Alternative road probably exists. |
| 13 | Lausasteintunnelen | Hordaland | @700m | ? | There is an old road around this tunnel along the lake shore. |
| 25 | Leiret | Hedmark | 85m | ? | Go via the local road. |
| 465 | Lervik | Vest-Agder | 800m | Unlit or poor lighting. | |
| 555 | Lianakk | Hordaland | 193m | ? | Go around the tunnel. |
 | 7 | Liaros | Hordaland | @500m | Yes | |
| E6 | Liervik | Nordland | 500 | Yes | |
| 155 | Ljabrudiagonalen | Oslo | 176m | ? | Take the cycle path. |
 | 60 | Ljønibbtunnelen | Møre og Romsdal | @ 3260m | ? | |
| E39 | Loga | Vest-Agder | 829m | ? | Go via the local road. |
 | E39 | Lote | Sogn og Fjordane | 2859m | Yes | None. |
| E16 | Lørdal | Sogn og Fjordane | 24509m | ? | Go via the Fv 243 (summer only). |
| 540 | Løvstakken | Hordaland | 2045 | ? | Go around the tunnel. |
| 555 | Lyderhorn | Hordaland | 1115m | ? | Go around the tunnel. |
| 57 | Lyngfjell | Hordaland | 966m | ? | Go around the tunnel. |
| E18 | Lysakerlokket | Akershus | 350m | ? | Go via the old Drammen road. |
| E7 | Måbø | Hordaland | 1893m | ? | Go around the tunnel (summer only). |
| 614 | Magnhildskaret | Sogn og Fjordane | @ 3110m | ? | |
| E136 | Måndalstunnelen | Møre og Romsdal | @ 2060m | ? | |
| E134 | Markhus | Hordaland | 2405m | ? | Go around the tunnel. |
| E39 | Masfjord | Hordaland | 4110m | ? | Go via Haugsdal. |
| E39 | Mastrafjordtunnelen | Rogaland | 4424m | ? | ? |
| 866 | Maursund | Troms | ? | ? | |
| 23 | Merraskott | Buskerud | 605m | ? | Go via the Rv65/ Kv/ Fv11/Kv Bjørnstad - Verpen. |
| E39 | Mitnes | Hordaland | 181m | ? | Go around the tunnel. |
| 569 | Modalen | Hordaland | @ 3830m | None | |
| E6 | Moelvtunnelen | Hedmark | 200m | ? | Go via the local road. |
| E6 | Mosodden | Oppland | 210m | ? | Go via the local road. |
| 19 | Mosseporten | Østfold | 293m | ? | There are several alternative routes around this tunnel. |
![]() | 13 | Myrkdalstunnelen | Hordaland | 1100m | Yes | None. |
| E10 | Nappstraument | Nordland | 2500m | Yes | There is a once a day ferry boat service - Nusfjord to Ballstad. |
| E6 | Narvik | Nordland | ? | ? | |
| 5 | Naustdal | Sogn og Fjordane | 5970m | ? | Go around the tunnel (over the hill). |
| 64 | Nebbetunnelen | Møre og Romsdal | 445m | ? | Go around the tunnel. |
| E16 | Nes tunnel | Buskerud | 1276m | ? | Go via the Fv155 + cycle path. |
| E6 | Nordbytunnelen | Akershus | 3850m | ? | Go via the R156 Ringes - Tusenfryd - Vassum. |
| E69 | Nordkapptunnelen | Finnmark | 6.9km | ? | |
| 13 | Oksla | Hordaland | 1231m | ? | Go around the tunnel. |
