i'm surprised no one mentioned road quality.
I-90 through Minnesota is HORRIBLE!!! Thump-thump-thump for 300 miles, border to border. We drove from MI to Yellowstone Sept. 2008, out I-80 (nice) back I-90 (fine in WY, SD, WI, IL, but not MN). Were I to drive it again, I'd take the interstate south from 90 near the SD/MN border to I-80

The ferry's about $110/car

I80 versus I70 - which one is better??
I just drove from Albany NY to Denver on I80 and had to come back via I70. For me, I much preferred I80 as being direct, easy to drive, no traffic jams, plenty of services available.
Some observations:
yes, there might be more to look at on I70, but this means you are passing closer to cities and are subject to traffic problems and many quick on and offs.
If you want to buy fireworks, take I70, we saw none on I80.
Tolls were way less on I70 - about $15 total, as opposed to $35 on I80 - EZ Pass worked the whole way on I80, but on I70, Kansas doesn't take EZ Pass.
I80 is shorter by a couple of hours, and if you're going to Boulder, you definitely want I80. Via I70 Kansas takes forever and then when you hit Colorado, you still have a long way to go to Boulder. Everyone complains about Nebraska on I80, but it was a straight shot, no traffic. There were some interesting things to see in Nebraska if you have the time - Pony Express Museum, Prairie Museum, Cookbook Outlet, all seemed to be close to the road. We found Iowa I80 to be a snooze other than the giant windmills, but it was also easy to drive.
In general we saw few cops ticketing on I80, actually saw none in Nebraska. On I70 in Kansas, it was COPS GALORE pulling everyone over.
Most of I70 is 70 mph speed limit, most of I80 is 75 mph - that was a big consideration for me.
So, for me, it's definitely I80!!!!

Paristhrice, you realize, of course, that you responded to a two year old question. I sure fromMA has been there and back a couple of times.

I'm actually happy to see this thread brought to the top, as I've been thinking about this myself.

So does I80 still take EZPass the entire way?
How about I70?

Also, is I80 still 75?
How about I70?

Anything other ideas out there?

Who cares about whether KS take EZ Pass or not? It's a short stretch $2.50 stretch with just one stop to get ticket and one to pay, and I doubt there's a long wait to pay.

Speed limit in IA and MO are both 70. But NE is 75 while KS is 70. If one is going to say, Denver, the stretch in NE is about 350 miles. 75MPH means 4:40; 70MPH means 5hr. One can easily get stuck in Chicagoland for more than 20 minutes.

There is no toll on I-80 from Chicago to Utah.

I hate I-70 across Missouri. One of the most unpleasent stretches of Interstate Highway in the country.

Crossing Kansas, there are a lot of interesting places to visit or eat if you get even a few mile off the Interstate.

My husband and I are leaving 7/14/17 CT. to Seattle Wa. Both ways by car. Back 7/27/17 any suggestions where to stop and what to see. The only thing we have planned is Rock n roll Hall of fame and Mount Rushmore. We're going to Wink it!

Yes

This thread is OLD OLD OLD>
Repost your question on a NEW NEW NEW thread

>> Yes <<

okaaaay - Yes what?

Definitely start a new thread . . . But you want to drive all the way across the country and <i>back</i> in 2 weeks? You are talking 6000 miles and about 100 hours butts in seats time. Or nearly 8 hours per day EVERY single day!