"I cannot go to work without it," said Lydia Saldon, who rides the CityLink bus to and from work everyday.
It's also a rather hot one, especially during summer months.
"Its hotter than outside sometimes," said Saldon.
This summer's triple-digit temperatures are taking a toll not just on CityLink's riders, but on the buses as well.
"You've got the heat radiating from the ground, the sun all over the vehicle so it makes the compressor work harder and longer before it achieves where it needs to go as cooling," said Kurt Hurick, CityLink maintenance supervisor.
The air conditioning system is usually the biggest problem.
The air conditioner is trying to heat your freon up and then cool it down and it's always doing its job and it's always hot.
People stepping in and outside of the buses is one of the key reasons for why they're extra hot on summer months, especially the para-transit buses where the doors have to remain open for longer periods of time.
Price increases in fuel and freon hasn't helped, but administrators say it hasn't affected their yearly budget just yet.
"The seven years I've been here I've watched air conditioning parts, freon and hoses accelerate over 60 percent," said Hurick.
CityLink administrators say they have plenty of spare buses so there should be delays whenever any need maintenance.
As for the uncovered bus stops, they've recently obtained a federal grant that will be used to add a few more shelters.
For now, mechanics continue to grin and bear the heat so riders wont have to.
"It's my only way to go to work so I can't do anything," said Saldon.