The car moved smoothly down the road.

In a manner that is free from difficulties or obstacles.
She spoke smoothly during the presentation.
The ice skater glided smoothly across the rink.
The software runs smoothly on my computer.
move smoothly
run smoothly
speak smoothly
easily
effortlessly
seamlessly
The car drove smoothly on the highway.

In a way that is even and without bumps or difficulties.
The ice skater glided smoothly across the rink.
She spoke smoothly during her presentation.
The river flowed smoothly through the valley.
drive smoothly
move smoothly
transition smoothly
evenly
seamlessly
effortlessly