Instead of sending drivers by the safer state highway route between Te Anau and Central Otago, the Google Maps navigational aid directs them to turn off just north of Riversdale on to Two Chain Rd, and then on to a secondary road via Wendon, Otama, Waikaka, Kelso, Heriot and Moa Flat to connect with SH8 at Ettrick.
That takes them through the Two Chain Rd-Riversdale-Waikaia Rd intersection known to locals as a black spot.
There were two serious crashes there in just over five weeks recently after motorists drove through a stop sign on quiet Two Chain Rd into traffic on the busier Riversdale-Waikaia Rd.
At the end of August, a campervan carrying two Italian tourists collided with a car, killing Sri Lankan farm worker Pradeep Edirisinghe (44), while in mid-July, a Nissan people-mover with four occupants was hit by a 4WD.
Cr Brian Dillon, who has lived in the area for many years, said locals had often seen campervans being driven on Two Chain Rd and wondered why, until they checked out Google Maps.
''I tried it myself and I couldn't believe what came up. It might be the shortest route, but it's not the safest route,'' Cr Dillon said.
For drivers unfamiliar with Southland, a safer route would be SH94 to Gore, then SH90 through Raes Junction, he said.
The Southland District Council is spending about $20,000 installing new flashing signs to warn approaching motorists of the Two Chain Rd stop sign, but Cr Dillon said he would like to see motorists directed to the safer route.
''I'm not sure if that will happen. It's a difficult thing to do anything about.''
Focus Technology managing director Rod Sinclair, of Invercargill, said ''no humans were involved'' in deciding which GPS routes would be suggested.
''It is likely a computer has made the decision using algorithms [problem-solving formulas] such as avoiding gravel roads.
There are not hundreds of people with local knowledge sitting in a room working on this.''
Senior Constable Adam Roberts, of Riversdale, said too many drivers relied on GPS and no longer carried print maps.
''Unfortunately, in the digital age, common sense has gone ... Drivers still need to be aware of their surroundings and need to concentrate.
Navigational aids are just that and shouldn't supersede good driver behaviour.''
With near misses at the intersection reported ''almost daily'', Snr Const Roberts said hehoped the new signs would work to reduce the issue.
The LED lights on the new signs were solar-powered and activated when a vehicle was detected within range of a radar, in the same way active school zone electronic warning signs operated, SDC safe system roading engineer Roy Clearwater said.
''To the best of my knowledge, this exact sign set-up has not been used here in New Zealand. However, I know other regions are exploring very similar if not the same set-ups.''
The $15,000-$20,000 cost was being split between the Southland District Council's roading budget and the New Zealand Transport Agency, he said.
It was hoped the signs would be installed next month.
Council group services and assets manager Ian Marshall said the council had already been looking at making changes at the intersection before the fatal crash ''upped the ante''.
He said he was perplexed about why some drivers failed to see the stop signs.
''Stop signs are universal with their octagonal shape and red colouring ... but we have to allow for people making mistakes.''
