Cheap lots Hollywood, California (hillside) what's the catch

[Mustafa I.]

On Trulia and Zillow, you can often find affordable, vacant residential home lots in and around Hollywood, Los Angeles. Home values in these areas are very high. However, these lots have usually the following characteristics:

• Prices are cheap, relative to the home values in the immediate surrounding, around 14k - 50k.
• The lots are usually around 3000 - 5000 sqft.- No physical street access however, you can always see new planed streets(?) on the plots.
• Lots are always behind another property with existing road access.
• Lots are on a (steep) slope

I understand that constructions on steep slopes are probably very cost-intensive, which is probably the reason why these lots are relatively cheap. But what about these planned streets (?) on the plot and utilities?

Could you help me to understand the following questions I have:

1. The new/future street on the plot has already a street name. (a) Does that mean that the City will go ahead and build/maintain the street? If so, (b) when will that happen, and (c) is that free of charge for the lot owner? There are usually at least 20 lots on these "planned streets".

2. Do I have to wait for the street to be built in order for me to start with the contraction of my home, or can I just drive on the "dirt way"/"planned roadway" to my property?

I am attaching the following examples below for demonstrational purpose:

https://www.zillow.com/homedet...

https://www.zillow.com/myzillo...

I feel like I am missing something. In Germany, where I am coming from, the city would be responsible to provide street and utilities to your plot of land as long as it is zoned as a residential area.