[rob74]

Where I live there is a stop sign before merging into a major road despite originally good visibility, so few people actually stopped, which apparently led to accidents. Then they installed some barriers to make visibility worse (so drivers will not see the traffic on the main road until shortly before the stop sign, more or less forcing them to stop and take stock of the traffic situation, unless of course they are very irresponsible). Not sure if this has improved safety, but the barriers have been there for some years now, so I guess they were at least a bit successful...