The driver must be able to see a warning that is given when air pressure in the service air tanks falls below what psi?

In a commercial vehicle, the air pressure in the service air tanks is critical for the functioning of the braking system. When the air pressure in these tanks falls below a certain threshold, it signals to the driver a potential issue that needs immediate attention.

The correct threshold for the warning signal is set at 60 psi. If the air pressure dips below this level, it indicates that the air brake system may not be able to function effectively, increasing the risk of brake failure. A warning at 60 psi allows the driver enough time to react and take necessary safety measures, such as pulling over and investigating the issue, before the brakes might become completely insufficient.

Understanding this critical pressure point enhances safety for the driver and all road users, as it emphasizes the importance of maintaining sufficient air pressure in the braking system.