Smooth traffic flow on the road.

道路交通顺畅。

youdao

The road was paved with smooth stone slabs.

道路用平整的石板铺成。

《牛津词典》

Afterward, time strode over me slowly, just like the road roller runs over the surface of an asphalt pavement that was not enough smooth.

后来，时间慢慢地从我身上走过，就像压路机在不够平整的沥青路面上碾过一样。

youdao

Ms. HOLIDAY: (Singing) Smooth road, clear day, but why am I the only one traveling this way.

NPR: New CD Set Celebrates Billie Holiday

Road test your team on the additional responsibilities in advance of your maternity leave, so if there are bumps in the road you can smooth them out.

FORBES: And Then Came Baby #2... Balancing Motherhood and Entrepreneurship

President GEORGE W. BUSH: I wish I could tell you that the violence is waning and that the road ahead will be smooth-it will not.

NPR: Bush Speech Highlights the Challenge of the Iraqi Insurgency