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I need to sit down and work it out on paper, but as a long standing reverse parking fan - I can't park forwards, as it's too difficult - I don't think the diagr

by tom_ 7y ago

I need to sit down and work it out on paper, but as a long standing reverse parking fan - I can't park forwards, as it's too difficult - I don't think the diagram shown here is quite right. When going backwards at low speeds, the fact there are two rear wheels is very important! When reversing when turning fully left, the left rear wheel stays pretty much where it is; when reversing when turning fully right, the right rear wheel behaves that way. OK - well, this is of course not quite true, because the car is moving, and so it's not quite rotating around a fixed point. But it's close enough that you can pretty much start your reverse parking manoeuvre by putting one wheel in the right place, so its contact point is lined up with wherever it ultimately needs to be - but it doesn't really matter which angle, provided it's within 45° or so. Then turn full lock in that direction (left for left wheel, right for right wheel), on the spot, and slowly reverse until the other wheel is lined up too. Now you're done. Straighten the front wheels and go in backwards. It's handy to bear in mind the swept volume, as there will be some overhang, but when going in backwards with this technique you don't typically have to worry about it too much. (Making the wheels turn on the spot is not the best thing, but you can fix this once you're confident with the basic manouevre.)

doublement 7y ago
Watch out for bikes and pedestrians please. Few people expect a car (especially on the other side of the street/lane) to drift by a space then reverse into it after passing it by.
- downerending 7y ago
  I've seen this. In addition, it's much harder to spot pedestrians that might suddenly enter the space (and may not have an easy way to get out).
  - jschwartzi 7y ago
    This is one of many reasons why parking maneuvers should be performed slowly. I once turned into a space to park only to encounter a woman on the other side of her housewife panzer tank. The only reason I didn't hit her was that I was going about 5 miles per hour the entire time, so when she came into view I could just put my foot on the brake and stop gently. Contrast this with drivers I've seen who will haul ass into a parking space at 15 MPH and then brake immediately.
- Hamuko 7y ago
  You should be expecting it if the car is indicating, which is something you should do when you're about to park.
  - doublement 7y ago
    If a person is walking north, about to walk past a parking space, and a car is heading south and signaling left, it's very surprising to see the car pass the person by, then suddenly reverse and try to enter the space. Once the car is past, most people assume it's signaling to turn farther along, instead of about to go backwards. EDIT: To be clear, I'm describing a perpendicular-parking scenario, where people usually make a right angle turn going forward to occupy the space.
mourner 7y ago
If you find any errors in the math, please let me know! I think the diagram supports your description — even with the wheel turned to the max, you will never hit anything close to the back wheel when reversing (both wheel axes are marked), although the geometry will depend on the car specs like wheel base, overhang lengths and car width (the viz is for my car, Hyundai i30 2018). Also, I just looked up top-down views of reverse turning on YouTube and it seems to match. [1] The problem in my case is that the road is so narrow that it's very easy to hit the barrier on the right when reversing while turning to the left — that was what prompted me to make the visualiation. [1] https://youtu.be/c3AgaHGbE1Q https://youtu.be/c3AgaHGbE1Q
saalweachter 7y ago
There's a chance I may hate you. I park in a standard parking garage, with forward angle parking and one way traffic flow. I occasionally encounter vehicles reverse parked, which confuses me, but whatever, but then also encounter vehicles driving backwards (well, forward facing, going against the posted signage) through the parking garage. This is always a big headache, because again, this is a one way parking garage, and for some reason THEY never seem to think they should back up or get out of the way of the person driving the correct way through the garage, so I always have to do some extra maneuvering and wait for them to pass, and I usually only have a small margin before the train arrives, and-- Assuming they are not simply idiots who can't follow the signs, my next assumption would be that these are the people who are reverse-parking, looking for a spot to back into. Anyway, if you have difficulty making the turning radius to pull straight into a forward angle parking spot, there is a very simple trick: make a three point turn, attempting to pull into the spot to the right of the empty spot, then when you are almost to the bumper of the parked car, back up and straighten out, which puts you at the perfect angle to drive straight into the angled spot now in front of you. It beats the pants out of getting halfway into the spot before realizing you're about to hit the car on one side or the other and trying to straighten out after the fact.
- Cougher 7y ago
  I nearly always reverse into parking spots. Reversing into a spot is easier because of where the turning is occuring. I don't need to pull in, reverse, and pull in again. I also have a narrower window of view that I have to look backwards at with two stationary cars instead of moving cars. Conversely, when I pull straight out, it's much easier to scan the entire field for moving cars and pedestrians. If you concerned that I'm backing toward you when I'm pulling in, I'd be doing the same thing when I'm pulling out.
  - saalweachter 7y ago
    Note that my concern isn't really about the technical superiority of forward or reverse angle parking, or whether people choose to park forward or reverse in perpendicular parking. It bothers me when people decide to ignore the marked direction of traffic flow in a garage or parking structure to facilitate their preferred parking style; if there were a reverse-angle parking garage I used where people went backwards through but to forward park I'd be just as annoyed.
hadlock 7y ago
Reverse parking works well for me, as if you can get the rear "inside" wheel on the line for the parking space, at full steering lock the car will generally rotate around that wheel which makes parking very predictable.

by tom_ 7y ago

doublement 7y ago

Watch out for bikes and pedestrians please. Few people expect a car (especially on the other side of the street/lane) to drift by a space then reverse into it after passing it by.

downerending 7y ago
I've seen this. In addition, it's much harder to spot pedestrians that might suddenly enter the space (and may not have an easy way to get out).
- jschwartzi 7y ago
  This is one of many reasons why parking maneuvers should be performed slowly. I once turned into a space to park only to encounter a woman on the other side of her housewife panzer tank. The only reason I didn't hit her was that I was going about 5 miles per hour the entire time, so when she came into view I could just put my foot on the brake and stop gently. Contrast this with drivers I've seen who will haul ass into a parking space at 15 MPH and then brake immediately.
Hamuko 7y ago
You should be expecting it if the car is indicating, which is something you should do when you're about to park.
- doublement 7y ago
  If a person is walking north, about to walk past a parking space, and a car is heading south and signaling left, it's very surprising to see the car pass the person by, then suddenly reverse and try to enter the space. Once the car is past, most people assume it's signaling to turn farther along, instead of about to go backwards. EDIT: To be clear, I'm describing a perpendicular-parking scenario, where people usually make a right angle turn going forward to occupy the space.

mourner 7y ago

If you find any errors in the math, please let me know! I think the diagram supports your description — even with the wheel turned to the max, you will never hit anything close to the back wheel when reversing (both wheel axes are marked), although the geometry will depend on the car specs like wheel base, overhang lengths and car width (the viz is for my car, Hyundai i30 2018). Also, I just looked up top-down views of reverse turning on YouTube and it seems to match. [1] The problem in my case is that the road is so narrow that it's very easy to hit the barrier on the right when reversing while turning to the left — that was what prompted me to make the visualiation. [1] https://youtu.be/c3AgaHGbE1Q https://youtu.be/c3AgaHGbE1Q

saalweachter 7y ago

There's a chance I may hate you. I park in a standard parking garage, with forward angle parking and one way traffic flow. I occasionally encounter vehicles reverse parked, which confuses me, but whatever, but then also encounter vehicles driving backwards (well, forward facing, going against the posted signage) through the parking garage. This is always a big headache, because again, this is a one way parking garage, and for some reason THEY never seem to think they should back up or get out of the way of the person driving the correct way through the garage, so I always have to do some extra maneuvering and wait for them to pass, and I usually only have a small margin before the train arrives, and-- Assuming they are not simply idiots who can't follow the signs, my next assumption would be that these are the people who are reverse-parking, looking for a spot to back into. Anyway, if you have difficulty making the turning radius to pull straight into a forward angle parking spot, there is a very simple trick: make a three point turn, attempting to pull into the spot to the right of the empty spot, then when you are almost to the bumper of the parked car, back up and straighten out, which puts you at the perfect angle to drive straight into the angled spot now in front of you. It beats the pants out of getting halfway into the spot before realizing you're about to hit the car on one side or the other and trying to straighten out after the fact.

Cougher 7y ago
I nearly always reverse into parking spots. Reversing into a spot is easier because of where the turning is occuring. I don't need to pull in, reverse, and pull in again. I also have a narrower window of view that I have to look backwards at with two stationary cars instead of moving cars. Conversely, when I pull straight out, it's much easier to scan the entire field for moving cars and pedestrians. If you concerned that I'm backing toward you when I'm pulling in, I'd be doing the same thing when I'm pulling out.
- saalweachter 7y ago
  Note that my concern isn't really about the technical superiority of forward or reverse angle parking, or whether people choose to park forward or reverse in perpendicular parking. It bothers me when people decide to ignore the marked direction of traffic flow in a garage or parking structure to facilitate their preferred parking style; if there were a reverse-angle parking garage I used where people went backwards through but to forward park I'd be just as annoyed.

hadlock 7y ago

Reverse parking works well for me, as if you can get the rear "inside" wheel on the line for the parking space, at full steering lock the car will generally rotate around that wheel which makes parking very predictable.