hi, we'll be travelling in a party of 9 (including 5 teens & 2 senior citizens) on our first 3-week road trip in the USA from Dec 10 to 31. We're flying into LA from Singapore and we're hoping to cover the Grand Canyon, Las Vegas, Yosemite, San Francisco and Los Angeles. Here's the driving route that I've pieced together from information I got off the internet:

LA - Anaheim (1 night)
Freeway 1

Anaheim - Palm Springs (1 night)
Take MacArthur Blvd. North to Highway 55, to Highway 91 East, to Highway 60 East, to I-10 East, exit at Highway 111

Palm Springs - Laughlin (1 night)
Freeway 10 – Freeway 95 to Needles / Bullhead City

Laughlin - Route 66 - Grand Canyon (2 nights)
Highway 40 to Kingman – Route 66 – Back to Highway 40 – Williams Route 64

Grand Canyon - Jacob's Lake - Kanab - St George - Las Vegas (3 nights)
Route 64 – US Route 89 north – Jacob Lake Route 89A to Kanab – thru Zion Canyon on Utah State Route 9 – at Mount Carmel Junction turn left into Interstate 15 – St George - Las Vegas

Las Vegas - Bakersfield (1 night)
Interstate 15 west to Barstow; Highway 58 west to Bakersfield

Bakersfield - Fresno - Yosemite (3 nights)
I-5 north to Highway 99 north to Fresno. In Fresno, take Highway 41 north into Yosemite National Park

Yosemite - Sonora - Modesto - San Francisco (4 nights)
Interstate 120 – Interstate 205 – Interstate 580

San Francisco - Monterey/Carmel - Morro Bay (1 night)
Highway 1

Morro Bay - Santa Barbara - LA (4 nights)
Highway 1

For places where we're spending one night, it's just to break the journey. Would like your advise - is this itinerary too ambitious? the driving routes - are there better routes to where we want to go? have i broken the journey in the right places?

One major concern is driving to and within Yosemite. I read that roads are steep and winding. We'll be hiring a 15-seater passenger van (only car category that's available to accommodate all 9 of us). Is there cause for concern? We're not used to driving in winter conditions because all we get here in tropical Singapore is either rain or sun with high humidity all year round.

Any advise/suggestion would be greatly appreciated. thanks much!