When i was a kid / much younger and pedaled a lot, then i always kept off the highways, and used smaller secondary roads to get around.
And still once a guy towing a camper dident give me enough space, so his camper hit my tent / gear on the back of my cycle and sent me head first into a ditch.
The guy dident even stop, but he did turn into a caravan centre up the road, so i got to give him a scolding there.
And the 3/4 foot wide cycle "path" on the side of a highway aint much, even for a experienced Danish cyclist, and cars do 80 km/h ( 50 MPH ) here, so any hit and it will be very bad for the totally unprotected cyclist.
Luckily you can turn to bicycle navigation in google maps and i assume you can here choose to only use roads with a proper bicycle path, or secondary roads where granted the speed are also 80 KMH / 50 MPH but at least the traffic load are much less on those roads.
PS. little Denmark have over 10.000 KM of dedicated bicycle paths, so no problem getting around in all of this little country in safety. ( from one end to the other of Jutland the largest part of Denmark its only 332 km as the crow fly )