"Video feed" - could be a block of monitors. The vidio card was connected to her computer.She is watching the junction of two streets.The security camera itself could be mounted on the opposite corner of the junction.

This phrase is used to described any video broadcast on the interenet which showns events, usually in an uninterrupted fashion, as they happen (live). It is also usually used to refer, and in this case I do think it refers to the streaming (or broadcasting) from a camera in a fixed position recording all activity at one spot on a 2 lane road.

HERE'S A DEFINITON OF STREAMING MEDID AND LIVE STREAMING:
Streaming media are multimedia that are constantly received by, and normally presented to, an end-user while being delivered by a streaming provider (the term "presented" is used in this article in a general sense that includes audio or video playback). The name refers to the delivery method of the medium rather than to the medium itself. The distinction is usually applied to media that are distributed over telecommunications networks, as most other delivery systems are either inherently streaming (e.g., radio, television) or inherently non-streaming (e.g., books, video cassettes, audio CDs). The verb 'to stream' is also derived from this term, meaning to deliver media in this manner. Internet television is a commonly streamed medium.

Live streaming, more specifically, means taking the video and broadcasting it live over the Internet. The process involves a camera for the video, an encoder to digitize the content, a video publisher where the streams are pushed to (or pulled from the encoder - depending on the encoder) and a Content delivery Network to distribute and deliver the content. The URL can then be viewed by end Users live
http://en.wikipedia.org/wiki/Streaming_media

In your context, it is implied that she was watching a traffic camera which thus allowed her to imagine being at the spot she was watching and thinking intensely about the activity or non activity at that spot.