I was reading an article about the last moon landing 40 years ago:
So what would have happened if the lunar vehicle had broken down? Would the astronauts have been able to walk back 7 km (4.35 miles) to the lander?
I had a lunch with Apollo 15 Command Module Pilot (he stayed in lunar orbit while is fellow astronauts landed) Al Worden, Apollo 15 was the first mission to carry a rover and this exact question came up during the lunch. Worden said that the astronauts should have been able to make it back even if the rover broke down. Their range was in part limited by this exact possibility.
I seem to recall they went to the furthest spot first and worked their way back so if the craft did break down they would the best chance at moonwalking back or perhaps hitching a ride from a moon person passing by.
The lunar rover didn’t take the astronauts further than they could have walked on their own. What it did was allow them to carry tools and rock samples along with them as they did. Had it failed, they would have had to abandon any samples with it and walk back.
Call AAA?
AAM!
What if they’d gotten lost?
“That’s the same crater. I’m telling you, we’re driving in circles.”
“We’re not driving in circles. All the craters look the same.”
“You should have turned left at that big rock. Why won’t you stop and ask somebody for directions? You never stop and ask somebody for directions!”
Did they have female astronauts back then?
“If you don’t hurry up, we will miss our flight!”
The Lunar Rover had a Navigation Computer aboard. The astronauts always knew how far away and in what direction the Lunar Module was.
If it worked like modern-day GPS, it would have navigated them into a quicksand swamp.
Don’t forget that 7km is a lot easier to walk/bounce in 1/6th of Earth’s gravity.
I think the tracks and footprints might have helped a bit as well 
We didn’t, but the Soviets did. Of course their Lunar plans involed a 2-person mission with only one cosmonaut actuly landing on the Moon.
“Recalculating!”
Although you have 1/6th the weight, you still have all the inertial mass, and that includes the mass of the suit and backpack - so this still requires the same effort to accelerate and decelerate and control the balance of, as on Earth. The whole kaboodle was nearly 100kg. The big problem with the suits was however the pressure. They ran them at about 4psi and pure oxygen, but even this low pressure was enough to make moving the joints take a lot of effort. The suits used designs like a bellows constant volume joint to try to manage the problem, but this wasn’t a perfect solution. The lunar walkers got tired pretty quickly. The worst problem wad the effort needed to grasp things, something that fortunately doesn’t impact upon the effort needed to walk home.
This was referred to as the walkback limit.
Well, it allowed them to travel much further by conserving their life support while riding in it (as opposed to having to walk, huffing & puffing and using up their oxygen the whole way). Essentially the drive out to the furthest point was a ‘free ride’, if the Rover had broken down at any point thereafter they could have always walked back, not having used nearly as much of their O[sub]2[/sub] as they would have if they walked out the whole way.
Like most transportation what it mostly saved was time. For what that thing weighed they could have probably had enough oxygen for a month. The rover allowed them to go further and easier on the limited time they had to work with.
Yeah, but six of one, half dozen of the other. The key time limiting factor for the lander missions was oxygen. I don’t have actual figures but I’m sure that, if they removed the weight of the Rover from the J-mission LMs, they could have added more water & some ham sandwiches to the LM without much trouble. But the EVA suits had a built-in limit of O[sub]2[/sub] and increasing that would have been a whole can of worms, involving either their redesign or some kind of refill station, both of which would have probably been much more trouble than the addition of the Rover. GM was given the contract to build the Rover in little more than 18 months, almost as an after-thought, so NASA went ahead and planned the missions as needed, with or without it.