subwayMap | A jquery plugin to render data as a subway map visualization | Data Visualization library

Two initial considerations: d3.create("svg") is rarely used in real D3 codes. Also, you don't have data appended to the DOM, just SVG elements you loaded (unless you're calling that "data").

Back to your question, you don't need path.bounds to make your code work, actually you don't even need d3.zoom. All you need is get the element's box (with getBBox) and do the appropriate transform.

The real problem, though, is that you need to wrap all the elements in a , because you cannot apply the transform to the root SVG in SVG 1.1 (apparently this is possible in SVG 2).

Here is a basic demo. In this demo I'm using an external SVG made with different elements (circle, rectangle, text...), which represents the SVG you're appending. You get this SVG with: