1. Roads: Roads are often depicted with varying thicknesses depending on their importance. Major highways might be thicker than local roads, and roads might be shown with dashed lines to indicate unpaved surfaces.

2. Buildings: Larger buildings (especially those in urban areas) are often represented as squares or rectangles with their roof shape or a distinctive symbol indicating their purpose (like a church or school).

3. Railroads: Railroads are usually symbolized by parallel lines, with symbols indicating if they are single or double track. Railroad crossings and stations might also be shown.

Bonus: Other human-made features you might find on a topographic map include:

* Bridges: Often depicted with a specific symbol.

* Tunnels: Sometimes represented with a broken line or a symbol.

* Dams: Often shown as a thick line across a river or valley.

* Power lines: Typically depicted as a dashed or dotted line.

* Airports: Indicated by a symbol that usually includes a runway.