A €200m upgrade on a section of road between Farranfore and Killarney will greatly improve road safety but could have a severe impact on two outdoor amenities in Kerry.
Ecologists contend that three of the four options for upgrading the N22 will harm the area known as the “Dark Wood”, as well as the Deenagh River.
Previous efforts to develop the road were abandoned in 2008 due to the recession after over €3m had been spent on planning and design works.
The proposed stretch of road will include a link to the N71 to help the heavy traffic congestion in Killarney; it will also allow easier access to Muckross and the Ring of Kerry and facilitate better public transport options in the region.
Four options have been proposed, and it is expected that a route will be picked and have planning permission sought for by mid-2022.
Among the concerns raised by Ecologists are its impact on the Dark Woods, an amenity just 1km north of Killarney, popular with locals.
Three of the four options would split up the mixed woodland and ruin its walking trails; ecologists are also concerned about how it would impact its wildlife.
Two of the options would also destroy a strip of the River Deenagh SAC.