The distance between earth and mars is around 33.9 million miles which is quite a distance away.
If you were to go to mars in a nuclear rocket it would take the nuclear rocket roughly 100 to 115 days to reach mars once it left earth.
If the rocket was slower or the spaceship was slower it would likely take a year or even 2 or 3 years to reach mars from earth.
Mars is a long ways away from earth so you need a good speed spaceship or rocket to reach the planet mars with the nuclear rocket.
If you were to drive the 33.9 million miles in a car it would take several years and possibly your lifetime to get to mars in a car if it were possible.
I would not want to drive 33 million miles on a road trip as they would be a very tiring road trip and you'd need to switch out cars because before you drove the 33 million miles in a car you'd wear out several cars and need a lot of money to buy new cars and all that gasoline.