Cyclists using the new Dunedin to Port Chalmers cycleway, when it is completed in three or four years, will be confronted by just one small obstacle - the hill on which the suburb of Roseneath stands.
The New Zealand Transport Agency has approved the funding of the $6.8 million, 8km cycleway and is finalising its construction strategy.
Over most of its length, the cycleway follows the flat land of the rail corridor along the edge of Otago Harbour.
However, at Roseneath, agency senior transport planner Phil Dowsett has the hill to deal with as he looks for the easiest route between Blanket Bay and Sawyers Bay.
The "preferred option" is for a short detour back to State Highway 88 and for the cycleway to continue through the Roseneath cutting on a widened verge, with a fence separating cyclists from other traffic.
A suggestion made to the Otago Daily Times this week that it might be possible for the cycleway to pass underneath Roseneath, via the rail tunnel, does not appear to be feasible.
When approached for reaction to the idea, KiwiRail senior communications adviser Ruth Larsen said there had not yet been any detailed discussions with the agency and the Dunedin City Council about the cycleway route, but she was clear about use of the 300m rail tunnel.
"A cycleway running through the tunnel is not possible as there are two sets of tracks in the tunnel due to a crossing loop; essentially like a passing lane for trains.
"As a general rule, operating railway tunnels and pedestrians or cyclists are not a good mix. We have no examples of other tunnels elsewhere in the country that allow this activity."
Port Chalmers community board deputy chairman Steve Walker, who has been promoting the cycleway for the past four years, said he was aware it would be impossible to use the tunnel.
"It was on our agenda many years ago, but through various discussions we were told that it's just an absolute non-starter," Mr Walker said.
It is understood that there is an old rail tunnel, next to SH88, but it was blocked off many years ago.
