Using a device called – we're not making this up – a retroreflect-o-meter, the team discovered that the difference in the reflective values of painted lines put down in the proper direction was great enough that they could sometimes last an entire year longer than if they were painted in the opposite direction.
These findings indicate that the transportation authorities could save quite a bit of money if they go the extra step of ensuring the lines are applied in the correct direction. Additionally, safety would be improved since the lines would be more clearly visible at night. Other more costly alternatives include adhesive tapes with glass beads already embedded in the proper direction. Who knew?