The four stretches—part of the Thalappady–Chengala segment in Kasaragod—are nearing completion with final construction and signage installation underway. To improve accessibility, signboards will now appear in Malayalam, English, and Hindi, following new NHAI guidelines.

However, the design compromises have sparked concerns. The median, originally expected to be 3–4 metres wide in a 60-metre six-lane highway, is now just half a metre. This has made it challenging to install signs at safe and visible heights. Curve warnings and speed limit signs are being placed at 5.5 metres—raising doubts over whether drivers can easily spot them, especially at high speeds.

The downsizing stems from a decision to reduce the highway width from 60 to 45 metres. Of this, the six-lane road occupies 27 metres, with two service roads on either side (6.75 metres each), two-metre-wide footpaths, and crash barriers beyond them.

Adding to the challenge, there's no space for the typical greenery used in wider medians to block headlight glare from oncoming traffic. In its place, authorities are now considering anti-glare reflectors to improve night-time visibility.

Spanning 644 km from Thalappady in Kasaragod to Mukkola in Thiruvananthapuram, NH 66 has been split into 22 stretches for construction. So far, only five are complete—leaving 17 still under development.

While crash guards—metal beam barriers placed strategically to prevent accidents—have been installed along footpaths and critical curves, experts stress that median design and sign placement must not be compromised in the interest of speedier project delivery.

As Kerala awaits the partial opening of NH 66, the focus remains not only on infrastructure completion but on ensuring it meets safety standards for long-term viability.