Visa issuance as in having to go into the immigration office and be processed (pay fee, get fingerprinted, photographed, asked more questions, etc). A visa can also be defined as the passport stamp with whatever conditions and length of entry is granted by immigration officials, and not necessarily what gets put into your passport at the consulate.

For now, Canadian citizens (not to forget U.S. citizens) get to stay in the car to cross for the most part as they don't need stamps in their passport (or "visa issuance") as above.

For trains headed from Vancouver to Seattle, there is immigration pre-clearance in Vancouver but there is an additional check (not sure if it is just customs, or both customs and immigration) when the train physically rolls across the 49th parallel at Blaine. Haven't heard if anyone precleared at Vancouver has been ejected from the train and escorted back across at Blaine. Not sure what the Toronto-Buffalo train procedure is and if non-visa exempt (as definition above) pax have to detrain and get visas issued.

Thread belows which is 2 years old says those who are not visa-exempt have to disembark to get processed.

http://www.canuckabroad.com/forums/t...lo-vt5159.html

That should be sufficient, unless of course the immigration official thinks you may overstay. No 100% guarantee of admission.