prepositions - What is the difference between 'located in' and 'located on'?

I am solving the TOEIC workbook, by the way, I faced conflict that doesn't match meaning I knew.

The problem is

The newest branch of the library is located in/on Pine Street.

I think either 'in' or 'on' have the same meaning. But the commentary said that 'be located in' is mainly writing in front of building name and city name.

I don't know what is correct?

Answer

Prepositions are so versatile in their usage that it's difficult to give exact rules on their usage. However, here is rough guideline from English Club: Prepositions of Place: at, in, on

In general, we use:

• at for a POINT



• in for an ENCLOSED SPACE


• on for a SURFACE

at Point                in ENCLOSED SPACE   on SURFACE   
at the corner           in the garden       on the wall
at the bus stop         in London           on the ceiling
at the door             in France           on the door
at the top of the page  in a box            on the cover
at the end of the road  in my pocket        on the floor

at the entrance         in my wallet        on the carpet
at the crossroads       in a building       on the menu
at the front desk       in a car            on a page

Using the OP, we have

The newest branch of the library is located on Pine Street.

You use on when you want to talk about a building and its relation to a street. Roughly, you can consider the street as a "surface" so that it follows the guideline above.

The street is not really a point, so we don't use at. However, a specific address, like 123 Pine Street, is considered a point. In such a case, you could use at:

The newest branch of the library is located at 123 Pine Street.

The street is not really an enclosed space, so we don't use in. However, a specific city, like Los Angeles, is consider an enclosed space. In such a case, you could use in:

The newest branch of the library is located in Los Angeles.

I think the commentary you mentioned is referring to this specific example above. Referring to "writing in front of building", it's possible to use in. For example, there could be a sign in front of the building that reads

Our collection of contemporary works is located in this building.

Here, you can use in because the building is considered an enclosed space.