Kannur: The work related to National Highway widening has been progressing steadily across the state, as four stretches of NH 66 are set to be opened on 31 May. According to NHAI sources, final-phase construction is ongoing in these four stretches, including the Thalappady–Chengala (39 km) segment. Work on installing sign boards has begun. Following new guidelines, the signboards will now be displayed in three languages—Malayalam, English, and Hindi.

However, the median (central divider) on the highway is only half a metre wide, creating difficulties in installing these boards. Boards indicating curves, speed limits, etc., will need to be placed at a height of 5.5 metres. If placed lower, vehicles might hit them. There is concern about whether drivers will be able to clearly see such tall signal boards. The issue arises because the original 60-metre-wide six-lane highway has been narrowed down to 45 metres. In a 60-metre-wide six-lane road, medians can be 3 to 4 metres wide.

On highways with a width of 60 metres, small plants are usually placed in the median and on both sides. But in Kerala, there is no space in the middle of the highway for ornamental plants. These plants also help block direct glare from the headlights of oncoming vehicles. As an alternative to plants, anti-glare reflectors are now being considered.

From Thalappady in Kasaragod to Mukkola in Thiruvananthapuram, National Highway 66 spans 644 kilometres and is divided into 22 stretches. Of these, 17 stretches are yet to be completed. The land acquired measures 45 metres in width. The six-lane road itself is 27 metres wide, with two service roads on either side, each 6.75 metres wide—making a total of 13.5 metres. Additionally, there are two-metre-wide footpaths (utility corridors with walkways), and beyond them, crash guards are installed.

A crash guard, also known as a metal beam crash barrier or guardrail, is a road safety device used on national highways to mitigate the severity of accidents. These barriers are typically made of sturdy metal beams and are strategically placed at locations prone to accidents, such as near embankments, curves, or where there is a risk of vehicles veering off the road.

Stretches ready for inauguration:
Thalappady–Chengala (39 km)
Vengalam–Ramanattukara (Kozhikode bypass – 28.4 km)
Ramanattukara–Valanchery (39.68 km)
Valanchery–Kappirikkad (37.35 km)