You really need a minimum of 7 days to make this trip worth your while. Otherwise I would recommend you fly to Calgary and do a loop from there.
I will direct you to this article for some thoughts on the itinerary and timing.
With only 5 - 6 days, you would be best served driving the 11 hrs straight from Vancouver to Jasper, spending two nights in Jasper, driving down the Icefields Parkway and having two nights in Banff, then a last day to get to Calgary.
The following is a 1 minute video showing you the main highway between Lake Louise and Jasper. I don't think you will have a problem driving on the right side of the road.
If you wanted a more city experience, you could come to Vancouver for perhaps 3-4 nights, then visit Whistler for 2 nights. It is only 2 hours drive north of Vancouver. That would give you some nice scenery on the way and a mountain experience.
No need to overnight in Kamloops.. it's only a 4 hour drive from vancouver.. I'd drive at least to Clearwater which will give you more time in Jasper..You MUST prebook accommodation in all your stops as it's the height of tourist season. I'd start booking now.
There is a holiday long weekend from July 29 to August 1. This is the absolute busiest time of the summer tourist season, and in Jasper, that weekend is usually a sell-out for all forms of accommodation. If you will be in the Rockies then, I would strongly suggest making accommodation reservations as soon as possible.
I am guessing that you are only planning to get to Kamloops because you are perhaps flying in that day? And so by the time you arrive, get through customs, get your luggage and get your car, its already going to be late in the day?
That's a really tight schedule. I would add an extra night in Jasper and just stop into Lake Louise before you get to Banff. You will regret not having time to get up the Maligne Valley nor up to the Mt. Edith Cavel glacier.
Thanks for the great advise.
I have 2 route Options:
2 vancouver-Banff-Lake Louise-Jasper-Banff-calgary
Which route is good, scenic and normally follow ?
which type of car is suitable for 4 PAX having 4 Big Bags , considering parking, driving.?
Both routes from Vancouver to the Rockies are very scenic, but the edge goes to the Vancouver-Banff route (route #2), which goes over Rogers Pass and Kicking Horse Pass. The disadvantage to Route #2 is that it is longer in total distance. It also has you driving highway 93, the Icefields Parkway, twice although this is not necessarily a disadvantage, as the route is so spectacularly scenic that it is well worth doing more than once (and the views are different northbound and southbound). However, with your tight schedule, I think I would favour route #1, because the distance is shorter. (Vancouver to Jasper is closer than Vancouver-Banff, and there is no repeat of the Icefields Parkway. Altogether, I think route #2 saves at least five hours of driving.)
On the way to Jasper, you might want to consider stopping at Clearwater, BC (one hour past Kamloops, four hours from Jasper), which will give you a chance to see Wells Gray Provincial Park. Helmcken Falls is one of the scenic attractions there. The next day, driving between Clearwater and Jasper, you will drive through Mt. Robson Provincial Park - Mt. Robson is the highest peak in the Canadian Rockies - and besides Mt. Robson, there are two sets of waterfalls (Rearguard and Overlander Falls) to see.
As to the car rental question, a minivan or SUV type of vehicle should have plenty of space for you all.
My vote would be for option 2. Hwy 1, say from Sicamous, Revelstoke, Glacier National Park, Golden, Field, Yoho National Park to Lake Louise, is arguably the more scenic than Hwy 5 and 16. Hwy 1 follows our national railroad and has some interesting historic sites to visit.
You will need a car in the category of "full size." for 4 pax and 4 bags. You can check out the options on any car rental website: Avis, Enterprise, National, Hertz.
Route via Jasper and then to Lake Louise and Banff to Calgary is better than going through the Rogers Pass. The transcanada #1 highway is goofy in the summer with transport trucks and the Calgary traffic heading to Okanagan. The route via Kamloops and Jasper is a lot more relaxing and staying in a spot such as Clearwater is a good idea. Well's Grey Park is another great idea. And there is a lot of construction on both sides of Golden. And spend more time outside of Banff rather than spending 3 or 4 nights there. It is a zoo in the summer and so is Lake Louise. Make sure you go to places such as Emerald Lake, Moraine Lake, Takakaww Falls, Hike to the end of Bow Lake and even stay at Num ti Ja Lodge at Bow Lake. (not sure of spelling) Take the Bow Valley Parkway between Lake Louise and Banff and not the #1 Highway. You will not see any wild-life as they have big fences along the road side. Stay at Places such as Baker Creek Chalets near Lake Louise or Castle Mountain Cabins and not in Banff unless you just want to shop, and eat. There really isn't much else to see in Banff or do except shopping and eating. Jasper is a lot quieter than Banff although it will be busy when you are there. Again, look for spots such as Becker's Bungalows near Jasper and stay outside of the town.