Separate topojson files to load faster

[joehand]

Could separate the original road (and other pieces)?

[joehand]

Or we could use properties like:

{
    "properties" : {
        "start" : {
            "road" : false,
            "interior" : true,
        },
        "intermediate": [
            {
                "step_num" : 100,
                "road" : false,
                "interior" : false,
            },
            {
                "step_num" : 105,
                "road" : true,
                "interior" : false,
            }
        ],
        "end" : {
            "road" : true,
            "interior" : false
        }
    }
}

Would that work? Then if the step is greater then step_num use that property...?