WisDOT's solutions for the Friendship State Trail (it runs along US 10 through the Appleton, WI area) includes one interchange where the trail was built under the crossroad:
https://maps.google.com/?ll=44.21623...06899&t=k&z=17
That is the US 10/WI 76 interchange just west of Appleton in unincorporated Winnebago County. It did help that WI 76 runs along the top of a ridge in that area. Yes, that's an active grade school at the bottom of the image.
----
Same trail and US 10 freeway at County 'CB' (unnamed Westside Arterial), the next interchange east and a bit closer 'in' in the metro area, still in unincorporated Winnebago County. This is the first interchange west of US 41 (a future interstate) and a major water/river crossing (Little Lake Butte des Morts) and includes a few semi-major office employers in the SE quadrant of the interchange:
https://maps.google.com/?ll=44.21788...06899&t=k&z=17
The trail is protected by the signals at this crossroad and then continues eastward as that dark line south of that tree line/hedgerow.
This trail is very busy and likely carries some legitimate commuter traffic during warm weather, especially at County 'CB'.