Interesting how changing up the side of the road drivers use elevated their attention, resulting in less accidents, until the activity became second nature again.
The relatively smooth changeover saw a temporary reduction in the number of accidents... These initial improvements did not last, however. The number of motor insurance claims returned to "normal" over the next six weeks
Traffic accident rates briefly dropped as drivers overcompensated for the increased risk from driving on the unfamiliar side of the road, before returning to the level following the trend prior to the changeover.
Yes, it's a thing that makes it hard for city planners and transport engineers when they test out new things. Any change often improves status quo in the start, so need to run it for long enough to actually gather valid data.
When I first visited Kuala Lumpur in Indonesia I was dumbfounded how there wasn't endless car accidents. The taxi from the airport was one of the scariest things in my life. Roads marked with 3 lanes had cars 5 abreast with scooters and motorbikes still finding just enough space to lane split.
It really seemed like chaos to me. Didn't see a single bingle.
The relatively smooth changeover saw a temporary reduction in the number of accidents... These initial improvements did not last, however. The number of motor insurance claims returned to "normal" over the next six weeks
Iceland saw a similar effect on "H-dagurinn" when they made the switch (https://en.wikipedia.org/wiki/H-dagurinn):
Traffic accident rates briefly dropped as drivers overcompensated for the increased risk from driving on the unfamiliar side of the road, before returning to the level following the trend prior to the changeover.