Bicyclette, it is not safe to ride against traffic.
Does that bike lane have a divider line for cyclists going in different directions? Most of the bike lanes I've seen are wide enough only for one cyclist. If that is the case and two cyclists approach each other, one will be forced into the auto lane... dangerous!
I don't know about the specific laws in your country, but here are some tips which may help. Autos move on the right in the US, so you might have to some adjusting. This is from http://www.bicyclesafe.com/:
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Collision Type #10:
The Wrong-Way Wallop
You're riding the wrong way (against traffic, on the left-hand side of the street). A car makes a right turn from a side street, driveway, or parking lot, right into you. They didn't see you because they were looking for traffic only on their left, not on their right. They had no reason to expect that someone would be coming at them from the wrong direction.
Even worse, you could be hit by a car on the same road coming at you from straight ahead of you. They had less time to see you and take evasive action because they're approaching you faster than normal (because you're going towards them rather than away from them). And if they hit you, it's going to be much more forceful impact, for the same reason. (Both your and their velocities are combined.)
How to avoid this collision:
Don't ride against traffic. Ride with traffic, in the same direction.
Riding against traffic may seem like a good idea because you can see the cars that are passing you, but it's not. Here's why:
1. Cars which pull out of driveways, parking lots, and cross streets (ahead of you and to the left), which are making a right onto your street, aren't expecting traffic to be coming at them from the wrong way. They won't see you, and they'll plow right into you.
2. How the heck are you going to make a right turn?
3. Cars will approach you at a much higher relative speed. If you're going 15mph, then a car passing you from behind doing 35 approaches you at a speed of only 20 (35-15). But if you're on the wrong side of the road, then the car approaches you at 50 (35+15), which is 250% faster! Since they're approaching you faster, both you and the driver have lots less time to react. And if a collision does occur, it's going to be ten times worse.
4. Riding the wrong way is illegal and you can get ticketed for it. Bruce Mackey says that 25% of cycling collisions are the result of the cyclist riding the wrong way.
There's one possible exception to riding the wrong way. When you're riding in the country on narrow, high-speed roads, it may be helpful to ride against traffic so you can see what you're up against. Compared to city traffic, country traffic is likely to have less roadspace for bikes and cars to share. That being the case, riding the wrong way allows you to bail into the shoulder if a car doesn't see you. You don't have problem #1 above because side traffic is rare, and #2 is avoided because you're riding primarily along one road and not turning right.
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Maybe you can check with your local law enforcement agency about the current laws and safety regualtions. Good luck!