Mixed freight & passenger trains

With the coalitions to bring back passenger rail to areas of Canada, has there been any thought of combining freight & passenger cars in order to cut costs & remain efficient?

Any experiences that people can share?

It might work, but with certain conditions to be met:
(a) Overnight. A 5-hr daytime journey that becomes 8-hr on a mixed train (because of lower speeds) is bearable if passengers can sleep.
(b) Few or no stops en route between starting point and destination. Gotta keep long freights moving.

That can be possible,but very limited...
A good possibility is to do econo-routes
like example,for regional low passenger frequency service.VIA can add some route that no passenger rail service is provided,even on CN,CP or regional railroad company..
Example for a route in the corridor Montreal/Toronto,for sure,we keep the actual service,but some station are desserved partialy like Côteau,we add a pasenger car on CN 308/309,it use to do car pick-up or delivery in the yard,by the same,pasenger can boarding on the passeger car that hauled by 308,and make a terminal stop at Dorval station,where passenger can have choice to get on next inbound Montreal train following,or take the bus to get in downtown..
the when comming back from Montreal to Côteau,take the train at Dorval to come back..

we can do some routes like that to deserve region that not rentable for a entire passenger set,and that have some freight only,by adding a coach car,they can reach area that are only accessible by car..

I eared about rumor that ONR did combine passenger and freight train,riding by scheduled structured operations..But rumor are never sure to be the real thing,but peopples that use to railfanning ONR can tell us more about this possibility..

It could work on trains that are already known for being a bit slower, Which would include everything except the Coridor, and to some extent, the Ocean. The Montreal-Senneterre route would be a perfect train to, at least, try this out =D