It interconnects the major towns of Punalur, Pathanapuram, Konni, Pathanamthitta, Ranni, Manimala, Ponkunnam, Pala, Thodupuzha to the main intersection at Muvattupuzha merging to MC Road which extends northwards till Angamaly at NH 66.

Punalur - Alimukku - Piravanthoor - Pathanapuram - Kallumkadavu Junction (joins SH 05) - Kalanjoor - Koodal - Konni - Kumbazha (Pathanamthitta, meets T.K.Road / SH - 07) - Mylapra - Ranni - Karikkattoor - Manimala - Cheruvally - Ponkunnam - Paika- Pala - Thodupuzha - Vazhakulam - Muvattupuzha (joins MC Road -SH 01) The economy of the High-Ranges of South and Central Kerala largely depends on the Main Eastern Highway.

Though it is the shortest route to Angamaly and Northern Kerala townships from Punalur, (The Second Largest City of Kollam District) and in turn from the Tamil Nadu townships Tenkasi, Tirunelveli and Thoothukudi.

It is also the Shortest route to the Kerala State Capital Thiruvananthapuram from Kumali and other major townships of Idukki district Like Munnar, Kattappana, Thodupuzha, Moolamattam, Nedumkandam etc.

The townships Punalur, Alimukku, Piravanthoor, Pathanapuram, Koodal, Konni, Kumbazha, Ranni, Manimala, Ponkunnam, Pala, Thodupuzha, Muvattupuzha comes under the Main eastern highway road The upgrading work of Punalur -Ponkunnam-Thodupuzha stretch is currently under progress as part of the World Bank funded Kerala State Transport Project (KSTP).