Noise-barrier tunnels made of flammable acrylic material that cover freeways around the country are set to be replaced in the wake of a deadly fire in such a tunnel last December.

The transport ministry unveiled the plan on Thursday during a ministers’ meeting on contentious issues chaired by the prime minister in Seoul, a decision seemingly made in response to the tragic fire that left five dead.

The ministry plans to first replace 58 noise-barrier tunnels made from acrylic with tunnels made from polycarbonate or reinforced glass, which are considered to be highly fire-resistant.

Experts believe that the highly flammable acrylic material served as kindling in last December’s fire.

The ministry’s decision comes after its inspection of 170 noise-barrier tunnels in the country found that 58 tunnels contained the acrylic in question, while 110 tunnels were found to be structures that would make evacuation and smoke dispersion difficult.

The ministry plans to first complete the replacement of such tunnels along national highways by the end of this year, while tunnels managed by local governments should be done by February of next year.