There are a lot of times when a vehicle will be in need of professional repair, but it can still technically be driven. But, should it be driven? That is what will be discussed here.
Your Brakes Or Rotors Need To Be Replaced
Even if you think you can still drive the vehicle, if your brake pads are almost completely gone, or they are gone and they are now digging into your rotors and destroying them, you shouldn't drive it. This is because at any moment you could find it incredibly difficult to stop. The same goes for if you have a leak in the brake lines. While you might have been able to continue to keep enough brake fluid in the system for now, you never know when that small hole in the brake line will become a large hole and you will lose all braking power and cause an accident. If you are dealing with any of those issues, it would be best if you simply have a tow truck take your vehicle to the mechanics for some repairs.
The Transmission Is Slipping Extremely Bad
At any moment, your transmission could go from working, but slipping, to completely frozen and you won't be able to move your vehicle. This could be the different of possibly repairing the existing transmission or having to completely replace it because it locked up. Therefore, if you have gotten to the point where you are ready to pay someone to repair your transmission, you might want to pay for a tow truck to take it in. The less strain you put the transmission through, the less likely it is to lock up before you have a chance to get it fixed.
The Engine Is Overheating
You will not want to continue to drive your vehicle if the engine is overheating. Even if the mechanic's repair shop is right down the street, it is better to call for a tow truck. Not only could continuing to drive with an overheating engine cause excessive wear on various parts, but the engine could completely lock up and then there is no hope in repairing it. At that point, you would simply have to pay for a brand new or rebuilt engine to be put in.
If you have a different mechanical problem and you are unsure if you should hire a tow truck or not, you will want to contact your mechanic. He or she will be able to give further advice for your particular situation.