Dangers of commuting outside town to work I live in the Canary Islands, more concretely, in Gran Canaria. Our towns are pretty spread on the island, and it is really common to live in one town and working in the capital, which on average is approximately 20 minutes by car.

Some of my coworkers come to work by bicycle, they live somewhere near. The one that lives furthest from the office has to make a 30m ride in his bicycle before he arrives at the office.

I was thinking about this idea, the difference is that I should make a 1h 30m trip (estimated by Google Maps): Which is this one: Google maps link

It involves roads without road shoulders and some parts with a cliff on the right (it has a crash barrier).

Being a beginner in long trips (actually never made one that took more than 30 minutes) I don't know if this one is too dangerous for taking it two/three times a week (I work on semi-remote).
I live in a rural area, and I am always looking for new roads.  Most of the roads here have no shoulder, and there are some cliffs.

The first thing that I do when I'm deciding whether a new road is too dangerous or not is to do a test-drive in a car.  I look to see where there is a shoulder and where there isn't, I look for blind curves, I look at the pavement quality, and I look to see how much traffic there is.

Next, I try riding the road when there isn't much traffic.  For me, the most dangerous thing is a blind curve where there is no shoulder; around here, people in cars like to pass me illegally in the blind curve.  The danger is that there will be a head-on collision between the car passing illegally and another car coming the other way; I don't want to be hit by the shrapnel.  If there are blind curves and no shoulders, then the traffic must be light or I won't use that road.

I would recommend that you have a look at your route in a car, and then try riding part of the route as a test when traffic is light, maybe early in the morning on Sunday.  If riding part of the way doesn't seem too risky, then try riding the entire route the next weekend.  If riding the entire route on early Sunday morning doesn't scare you, then try riding it early in the morning on a weekday.  If that is OK, then try your plan of riding to work two or three times a week.

I would also recommend that you find some local cyclists with more experience, and ask them about your route.  Maybe they can recommend some alternatives around the most dangerous parts.  Also be as safe as you can: wear bright colors and have flashing lights, use a mirror on your helmet, carry identification, and tell someone about your exact plans when you ride.