In my experience as Executive Director of Billings TrailNet, I have had many interactions with people (both drivers and bicyclists) who believe it is safest and most practical for people to ride their bikes on the sidewalk.

While some feel this is a good idea and are welcome to ride that way when it is legal to do so (NOT in business districts in Billings), I choose to ride in the street and recommend it for anyone who feels comfortable riding in traffic.  Riding in the street makes us more predictable to traffic because they know we’re acting as a vehicle. Drivers expect bicyclists riding on the street to move forward unless they signal their turn with their arms, and likewise, will be looking in the lane, not always the sidewalk, when they are exiting driveways and cross streets.

The League of American Bicyclists has created an informative video about riding on a sidewalk vs. riding in a lane: https://bikeleague.org/content/riding-sidewalk.

Children however, are better off riding on a sidewalk as long as they know cars may not see them or stop for them.  Many children, even on their bikes, are smaller than the cars and trucks on the road and thus, can be less visible to drivers. Additionally, not all children (or adults) have full control of their bikes at all times, and weaving in and out of a bike lane can be extremely hazardous.