There are quite a few between Canada and the US. Ten minutes in Google Earth came up with these:
BC-99 and former US-99, now I-5
BC-97 and US-97
BC-395 and US-395
BC-95 and US-95
BC-93 and US-93
MB-83 and US-83
MB-75 and US-75
MB-89 and MN-89
MB-310 and MN-310
ON-11 and MN-11
ON-71 and US-71
ON-61 and MN-61
QC-225 and VT-225
QC-235 and VT-235
QC-139 and VT-139
QC-243 and VT-243
QC-141 and VT-141
NB-95 and I-95
I've been over the first three crossings.