3 ms·

try: brakes() except BrakeFailure: emergency_brakes()

abakker 11y ago
Yes, but have you ever stopped with your eBrake? first, it doesn't usually effect all 4 wheels, and second, it isn't antilock. If, traveling 60mph your master cylinder or brake lines fail, the E Brake might not do the job. I know the E Brake in my Toyota Tundra wouldn't stop me if I were going 60mph. Again, my point was not to say that this was likely to happen, but merely that we should ensure that there is framework for dealing with these kind of scenarios where a car needs to choose. According to the document I shared earlier, 95% of accidents are driver error somehow. Self-driving cars are sure to improve those statistics, but for public acceptance we need to answer the other 5% of accidents too. EDIT: as Saberworks below points out, there is no Emergency Brake in the Tundra, or in fact almost any modern car. I was loosely equating the parking brake with an emergency brake because in many cars there is no "emergency brake", so the parking brake is your only other choice.
- cmdrfred 11y ago
  The first part sounds like a design flaw of your Toyota Tundra rather then a self driving car issue. Secondly, is it considered a mechanical failure when the master cylinder fails and the driver is too slow to find the emergency brake actuator in time? Self driving cars do not suffer from that problem.
- saberworks 11y ago
  Most people think of the parking brake as an emergency brake for some reason. These things are wimpy brakes that are designed to prevent a vehicle from rolling if parked incorrectly or on a hill. They are generally cable actuated and don't have much stopping force if the vehicle is in motion. The Tundra has a foot-activated ratcheting parking brake and I don't recall it ever being referred to as an "emergency brake" in the manual (although it's been a while since I read mine, I could be wrong).
  - protomyth 11y ago
    "Most people think of the parking brake as an emergency brake for some reason" Some car manuals actually labeled it "emergency brake".
  - mikestew 11y ago
    Most people think of the parking brake as an emergency brake for some reason. That's because that's what it used to be called. In the owner's manual. I imagine the change might be due to liability more than anything else. That, and just marketing. No one wants to imply that you'll have an emergency in your shiny, new Chrysler. These things are wimpy brakes that are designed to prevent a vehicle from rolling if parked incorrectly or on a hill. They are generally cable actuated and don't have much stopping force if the vehicle is in motion. Fifty years ago, this would describe most brakes on consumer vehicles [0]. They're wimpy because they're drum brakes (though more upscale vehicles have rear discs). They are difficult to modulate because they're actuated by flexy cables. But cable-actuated drum brakes were what you got when you bought a 1960 Chevy. As for stopping force, a parking brake should have all of the stopping power that the rear brakes usually have. The reason they often don't have much stopping power is because most people don't have them adjusted regularly (meaning the cable runs out before the full power available is applied), or more commonly they don't use it at all and the cable rusts up. If properly maintained, you should be able to lock the rear wheels at speed. [0] EDIT: give or take. I don't remember exactly when cars went hydraulic, and the web's no help. I did own a 60's Harley/Aramachi motorcycle that had cable-actuated brakes, FWIW.

Yes, but have you ever stopped with your eBrake? first, it doesn't usually effect all 4 wheels, and second, it isn't antilock. If, traveling 60mph your master cylinder or brake lines fail, the E Brake might not do the job. I know the E Brake in my Toyota Tundra wouldn't stop me if I were going 60mph. Again, my point was not to say that this was likely to happen, but merely that we should ensure that there is framework for dealing with these kind of scenarios where a car needs to choose. According to the document I shared earlier, 95% of accidents are driver error somehow. Self-driving cars are sure to improve those statistics, but for public acceptance we need to answer the other 5% of accidents too. EDIT: as Saberworks below points out, there is no Emergency Brake in the Tundra, or in fact almost any modern car. I was loosely equating the parking brake with an emergency brake because in many cars there is no "emergency brake", so the parking brake is your only other choice.

cmdrfred 11y ago
The first part sounds like a design flaw of your Toyota Tundra rather then a self driving car issue. Secondly, is it considered a mechanical failure when the master cylinder fails and the driver is too slow to find the emergency brake actuator in time? Self driving cars do not suffer from that problem.
saberworks 11y ago
Most people think of the parking brake as an emergency brake for some reason. These things are wimpy brakes that are designed to prevent a vehicle from rolling if parked incorrectly or on a hill. They are generally cable actuated and don't have much stopping force if the vehicle is in motion. The Tundra has a foot-activated ratcheting parking brake and I don't recall it ever being referred to as an "emergency brake" in the manual (although it's been a while since I read mine, I could be wrong).
- protomyth 11y ago
  "Most people think of the parking brake as an emergency brake for some reason" Some car manuals actually labeled it "emergency brake".
- mikestew 11y ago
  Most people think of the parking brake as an emergency brake for some reason. That's because that's what it used to be called. In the owner's manual. I imagine the change might be due to liability more than anything else. That, and just marketing. No one wants to imply that you'll have an emergency in your shiny, new Chrysler. These things are wimpy brakes that are designed to prevent a vehicle from rolling if parked incorrectly or on a hill. They are generally cable actuated and don't have much stopping force if the vehicle is in motion. Fifty years ago, this would describe most brakes on consumer vehicles [0]. They're wimpy because they're drum brakes (though more upscale vehicles have rear discs). They are difficult to modulate because they're actuated by flexy cables. But cable-actuated drum brakes were what you got when you bought a 1960 Chevy. As for stopping force, a parking brake should have all of the stopping power that the rear brakes usually have. The reason they often don't have much stopping power is because most people don't have them adjusted regularly (meaning the cable runs out before the full power available is applied), or more commonly they don't use it at all and the cable rusts up. If properly maintained, you should be able to lock the rear wheels at speed. [0] EDIT: give or take. I don't remember exactly when cars went hydraulic, and the web's no help. I did own a 60's Harley/Aramachi motorcycle that had cable-actuated brakes, FWIW.