Developed countries tend to build tunnels for lengthy mountain routes for which there is serious demand, so there is less a case for flying cars here.

Here in Norway we have a lot of fjords with small communities all over. The roads are narrow, twisty and often at high risk of falling rocks[1].

Due to the many roads and relatively few people using a lot of these high-risk roads, maybe flying cars would be a more cost-effective option here... would possibly also reduce the need for expensive ferries[2].

[1]: https://www.nrk.no/vestland/ras-i-roldal-isolerer-ti-fastboe...

[2]: https://www.nrk.no/nordland/bjornar-skjaeran-i-arbeiderparti...

Top Gear did a race from Italy to the UK. Clarkson driving a Bugatti Veyron, Hammond and May flying in a Cessna 182. They couldn't fly over the mountains, and May wasn't qualified to fly at night. It didn't save a lot of time.

https://www.youtube.com/watch?v=yoK4QYwixDc

Not sure which bits you could cut with a flying car - the safety checks, air traffic control involvement, runways, refuelling stop, qualifications/licenses, but it would have to be a lot to make a large difference.

I can drive from Como to Lugano in Switzerland in 30 minutes.

I guess the Alps are not a big issue.