It won't stop reckless driving on roads where the legal limit is way above the practical limit.
Although I have absolutely zero stats to backup my argument, I'd say deaths on twisty country roads where the vehicle was under the legal speed limit far exceeds those on straight motorways breaking the limit.
Here in rural Ireland there are plenty of roads with 80km/h speed limit where even the rally stages (on closed roads) can't reach it - hence the racing!
Unfortunately rural Ireland is also a pretty dangerous place to walk due to some pretty high speeds on some pretty small roads :-/ . Too often the council "upgrades" a road and in the process takes it away from people walking or biking.
Same. I had a beautiful home on a few acres of land with an old bog road from the 19th century near me (it's in the video I linked a lot) and cycling on that was a dream, but as soon as I tried to use the cycle lane to Tullamore it was a disaster of lorries and tractors trying to use said lane to pass each other.
Although I have absolutely zero stats to backup my argument, I'd say deaths on twisty country roads where the vehicle was under the legal speed limit far exceeds those on straight motorways breaking the limit.