How wide is a car door?

[JohnBrooking]

Therefore, how wide is the door zone? I could take some measurements myself, but of course they will vary somewhat by model. I'm figuring probably 3-4 feet, but I wonder if there are any official numbers given in any street design guide somewhere. Anyone know?

[kalliergo]

Check John Allen's work first:

http://www.bikexprt.com/bikepol/facil/lanes/doorwidth.htm

I have other references, if that doesn't get you going in the right direction...

[Brian Ratliff]

I've heard 4-5 feet for the door zone - this is from Hurst's book.

[Severian]

Don't car companies publish specs for these sorts of things? We could just find the largest one available (Bet you it's a cadillac or lincoln or buick) and make the door space 2 more feet beyond that.

[JohnBrooking]

Thanks for the replies. John Allen's page gives total vehicle widths for sampled vehicles ranging from 103 to 123 inches (8'7" to 10'4"), including 6" away from the curb. But he doesn't break it down by just door width and vehicle width with door closed, so I don't have just the door numbers. Nonetheless, taking into account width of handlebars, he claims that gives only 10-15" of non-door zone tire track space in the left part of a 5' bike lane next to a 7' parking lane, configurations supported by both AASHTO and the Chicago manual. (I'm not sure what math he's using, I get between 8" and 2.5'.)

FWHA states 2.4m (7.8') to be a standard car width, so add Hurst's 4', and you have close to 12', which leaves nothing outside the door zone in a 5' bike lane next to a 7' parking lane!

[kalliergo]

FWHA states 2.4m (7.8') to be a standard car width, so add Hurst's 4', and you have close to 12', which leaves nothing outside the door zone in a 5' bike lane next to a 7' parking lane!

I think that's pretty much accurate, in the real world. IOW, almost no North American bike lanes striped next to parked cars are safe to cycle in.

[wahoonc]

And in the real world they park more than 6" away from the curb...

Aaron:)

[Helmet Head]

I've heard 4-5 feet for the door zone - this is from Hurst's book.
I don't have the book in front of me, but I could have sworn he said 4 feet, or 3-4 feet. I remember thinking it was on the low side.

[sggoodri]

See the article "Bicycling and on-street parallel parking" at http://www.humantransport.org/bicycledriving/library/door_zone.pdf

4 door
1996 Saturn wagon, 35"
1997 Ford Taurus, 35"
1998 Town & Country van, 35"
1999 Suburu Legacy wagon, 36"
2001 Honda CRV, 36"
2001 Escort, 36"
1995 Honda Civic, 37"
1999 Jeep Gr. Cherokee, 39"
1995 Nissan Maxima, 40"
1995 Lincoln Town Car, 40"



2 door
1988 Chevrolet C1500, 37"
1994 Geo Metro, 39"
1996 GMC 3/4 ton, 39"
1990 Tempo, 44"
1991 LeBaron, 44"
1996 Chevrolet Z28, 44"
1996 Monte Carlo, 45"
1999 Cavalier, 45"

Open door length data provided by Fred Oswald, Richard Moer, Ken Clark, and Wayne Pein.

[Brian Ratliff]

I don't have the book in front of me, but I could have sworn he said 4 feet, or 3-4 feet. I remember thinking it was on the low side.

Could be. 3' is probably too low, you'd potentially hit the door, but then again, at 3', you would probably have enough time to react to the door opening if you were vigilent. Closer than that, probably not.

[Helmet Head]

but then again, at 3', you would probably have enough time to react to the door opening if you were vigilent. :eek:

Common misconception alert!

Time to react? Maybe... but "react" in what manner? Time enough to swerve left to avoid hitting the door, right into the path of the bus that is about to pass you at a speed differential of 10 mph?

Here's the worst part: your speed doesn't matter. You can be crawling at 3 mph, and if a door suddenly swings out and hits you in the handlebars or leg or something, it could instantly cause you to fall into traffic.

The only way to deal with dooring is to stay COMPLETELY out of the door zone, period. No exceptions. That should be your habit.

[kalliergo]

The only way to deal with dooring is to stay COMPLETELY out of the door zone, period. No exceptions.

Absolutely right.

[JohnBrooking]

So if you want a completely safe 5' bike lane, next to a 7' parking lane, what is really needed is 4' of crosshatching between the bike and parking lane to indicate no one should be there (except on your way to or from your parking space). Is this ever done?

That would mean Chicago's minimum 44' road width (10' travel lane, 5' bike lane, 7' parking lane, on each side) turns into a requirement for 52'.

[Brian Ratliff]

:eek:

Common misconception alert!

Time to react? Maybe... but "react" in what manner? Time enough to swerve left to avoid hitting the door, right into the path of the bus that is about to pass you at a speed differential of 10 mph?

Here's the worst part: your speed doesn't matter. You can be crawling at 3 mph, and if a door suddenly swings out and hits you in the handlebars or leg or something, it could instantly cause you to fall into traffic.

The only way to deal with dooring is to stay COMPLETELY out of the door zone, period. No exceptions. That should be your habit.

Reactions are always a "for better or for worse" deal. I'll venture that a bike messenger with several years of experience has his lines drawn more finely than you do.

And don't worry. I don't make it a habit to ride in door zones. I stand by my 4-5' rule for cyclists with my level of experience. Messengers... they have their own rules as they are more informed of traffic patterns and their own limitations than other cyclists generally.

[sggoodri]

So if you want a completely safe 5' bike lane, next to a 7' parking lane, what is really needed is 4' of crosshatching between the bike and parking lane to indicate no one should be there (except on your way to or from your parking space). Is this ever done?

That would mean Chicago's minimum 44' road width (10' travel lane, 5' bike lane, 7' parking lane, on each side) turns into a requirement for 52'.

Yes; one must wonder whether some of these minimum "standards" are really motivated by safety, or by a desire to shoe-horn bicycle-specific markings into the road for the sake of having bicycle-specific markings.

[bigpedaler]

i don't measure -- by eyeball, it's pretty simple; take at least 1/3 of the lane when approaching parked cars, and let the whiners honk. so far, only one honker in the last 14 months.

[AndrewP]

The lane width taken by an opening door is less than the door width, because the doors do not open to 90 degrees and the hinge is usually aft of the front edge of the door.

[randya]

It depends on the car.

[skanking biker]

:eek:

Common misconception alert!

Time to react? Maybe... but "react" in what manner? Time enough to swerve left to avoid hitting the door, right into the path of the bus that is about to pass you at a speed differential of 10 mph?

Here's the worst part: your speed doesn't matter. You can be crawling at 3 mph, and if a door suddenly swings out and hits you in the handlebars or leg or something, it could instantly cause you to fall into traffic.

The only way to deal with dooring is to stay COMPLETELY out of the door zone, period. No exceptions. That should be your habit.


Great post

[genec]

:eek:

Common misconception alert!

Time to react? Maybe... but "react" in what manner? Time enough to swerve left to avoid hitting the door, right into the path of the bus that is about to pass you at a speed differential of 10 mph?

Here's the worst part: your speed doesn't matter. You can be crawling at 3 mph, and if a door suddenly swings out and hits you in the handlebars or leg or something, it could instantly cause you to fall into traffic.

The only way to deal with dooring is to stay COMPLETELY out of the door zone, period. No exceptions. That should be your habit.

Huh, reaction time for you shouldn't matter. You're the one that says you can avoid a collision from a car that leaves the stop line on a narrow residential street as you enter the intersection... while you are moving at 20MPH.

With reactions like that, you should always be able to ride in the door zone. I don't get it. :rolleyes:

[2manybikes]

Thanks for the replies. John Allen's page gives total vehicle widths for sampled vehicles ranging from 103 to 123 inches (8'7" to 10'4"), including 6" away from the curb. But he doesn't break it down by just door width and vehicle width with door closed, so I don't have just the door numbers. Nonetheless, taking into account width of handlebars, he claims that gives only 10-15" of non-door zone tire track space in the left part of a 5' bike lane next to a 7' parking lane, configurations supported by both AASHTO and the Chicago manual. (I'm not sure what math he's using, I get between 8" and 2.5'.)

FWHA states 2.4m (7.8') to be a standard car width, so add Hurst's 4', and you have close to 12', which leaves nothing outside the door zone in a 5' bike lane next to a 7' parking lane!

I don't know the dimensions, but I ride on a road with a painted bike lane, right next to a parking lane once in a while in Providence. Typically when someone opens the door the whole lane is taken.

[Helmet Head]

:eek:

Common misconception alert!

Time to react? Maybe... but "react" in what manner? Time enough to swerve left to avoid hitting the door, right into the path of the bus that is about to pass you at a speed differential of 10 mph?

Here's the worst part: your speed doesn't matter. You can be crawling at 3 mph, and if a door suddenly swings out and hits you in the handlebars or leg or something, it could instantly cause you to fall into traffic.

The only way to deal with dooring is to stay COMPLETELY out of the door zone, period. No exceptions. That should be your habit.
Huh, reaction time for you shouldn't matter. You're the one that says you can avoid a collision from a car that leaves the stop line on a narrow residential street as you enter the intersection... while you are moving at 20MPH.

With reactions like that, you should always be able to ride in the door zone. I don't get it. :rolleyes: Gene,

I can't make sense out of this. Are you just looking for an excuse to harass me about something I wrote (and you apparently misinterpreted) in some other thread (which would be in violation of the harrassment and disruption guidelines - which luckily for you are not enforced) , or do you have a point relevant to this discussion? Because if it's the latter, I don't see it.

No matter how fast someone's reaction time is, the only way to avoid a suddenly opening door is to swerve left, possibly into traffic.

Having a fast reaction time is irrelevant. In fact, a slow reaction time might pay off here, because smashing into a door is probably better than swerving in front of a car, truck or bus....

[Helmet Head]

Reactions are always a "for better or for worse" deal. I'll venture that a bike messenger with several years of experience has his lines drawn more finely than you do.

And don't worry. I don't make it a habit to ride in door zones. I stand by my 4-5' rule for cyclists with my level of experience. Messengers... they have their own rules as they are more informed of traffic patterns and their own limitations than other cyclists generally.
I suppose those messengers with unbelievably fast reaction times and incredible bike handling skills could slide the bike under the door as they jump over the door, and rejoin on the other side.

[genec]

Gene,

I can't make sense out of this. Are you just looking for an excuse to harass me about something I wrote (and you apparently misinterpreted) in some other thread (which would be in violation of the harrassment and disruption guidelines - which luckily for you are not enforced) , or do you have a point relevant to this discussion? Because if it's the latter, I don't see it.

No matter how fast someone's reaction time is, the only way to avoid a suddenly opening door is to swerve left, possibly into traffic.

Having a fast reaction time is irrelevant. In fact, a slow reaction time might pay off here, because smashing into a door is probably better than swerving in front of a car, truck or bus....

Harrass you... no way... just trying to point out the realities of the road. Personally I stay well clear of door zones too. But you have told me that your superior training would keep you out of some situations (http://www.bikeforums.net/showthread.php?t=273257&highlight=point+of+no+return)that others have been injured in.

I thought perhaps you could avoid opening doors at 3MPH too.

Guess I am wrong.

So cars leaving the driveways or limit lines as you enter the intersection might be difficult to dodge perhaps?

[Helmet Head]

I thought perhaps you could avoid opening doors at 3MPH too.
No way. 3 MPH is 4.4 feet/second, or about 2 feet in half a second.

If a door suddenly opens just as you're passing it, it can easily push you falling right into traffic.

I think a common misconception about dooring is that the main thing to avoid is slamming into the door. I disagree. To me, that seems of secondary importance to avoiding swerving into, or being pushed into, traffic.

So cars leaving the driveways or limit lines as you enter the intersection might be difficult to dodge perhaps?
Of course they might be difficult, even impossible, to dodge if you ride too close to them. That's why you avoid the "strike zone" in front of them for the same reason that you avoid the "door zone" to the side of parked cars.

It's also why you avoid the "strike zone" behind cars parked at an angle (think north-side/westbound-side of Eastgate Mall between Regents and Genessee), or downtown Encinitas.

[Brian Ratliff]

I suppose those messengers with unbelievably fast reaction times and incredible bike handling skills could slide the bike under the door as they jump over the door, and rejoin on the other side.

No, I am suggesting that they know better the pattern of motions that a person makes as s/he is opening the car door and knows exactly where the line is between avoidance and collision. They spend 50 hours a week out in dense city traffic, year round, for several years. It's not 3 feet vs. 4 feet for them. It's "this women is still digging in her purse" -> 2 feet (if door opens, it won't be fast). "Man with shoulder hunched up looking into mirror" -> 5 feet. Or, of course, "no head in the window" -> 0 feet. Etc. There is no need for reaction times if you can anticipate accurately.

Set rules are for the relatively inexperienced cyclists, such as you or I. Experienced professional cyclists, such as bike messengers, shave things closer because they know how people move and react in accordance to different stimuli. And if they screw up, they know how to mitigate the damage. You and I need set rules to stay out of danger with significant safety margins. After all, we only ride in traffic a few hours each week. If you are like me, it is likely you spend no more than 4 hours a week exposed to significant workday traffic in a dense city.

That's childs play for a messenger. Even when you tack on the 4 hour group ride on the weekend, you are still not up to one day's work for a bike messenger.

[Helmet Head]

No, I am suggesting that they know better the pattern of motions that a person makes as s/he is opening the car door and knows exactly where the line is between avoidance and collision. They spend 50 hours a week out in dense city traffic, year round, for several years. It's not 3 feet vs. 4 feet for them. It's "this women is still digging in her purse" -> 2 feet (if door opens, it won't be fast). "Man with shoulder hunched up looking into mirror" -> 5 feet. Or, of course, "no head in the window" -> 0 feet. Etc. There is no need for reaction times if you can anticipate accurately.
Another common misconception alert... that it is possible to "read" potential dooring situations with sufficient accuracy to risk riding in the door zone.

It is not possible to anticipate the actions of people who you can't see. Even in a line of parked sedans (not panel vans) without tinted windows, you can't see the 4'10" driver reaching for the door handle because he is hidden by the seat and headrest... How about the kid in the back seat opening the rear driver-side door? How about that panel van? Camper? Delivery truck? Etc. etc.

I didn't realize riding in traffic 50 hours per week produces X-ray vision.


Set rules are for the relatively inexperienced cyclists, such as you or I.
Oh, please, I've had enough of your condescending attitude (whether you include yourself or not), Brian. Yes, I suppose "look back before merging" is a "set rule" for the relatively inexperienced too.

Experienced professional cyclists, such as bike messengers, shave things closer because they know how people move and react in accordance to different stimuli.
I'm sorry, I guess I missed that Saturday morning show about your bike messenger superheros. Oh, my Lord, this is too much. You are cracking me up, big time.

And if they screw up, they know how to mitigate the damage. You and I need set rules to stay out of danger with significant safety margins. After all, we only ride in traffic a few hours each week. If you are like me, it is likely you spend no more than 4 hours a week exposed to significant workday traffic in a dense city.

That's childs play for a messenger. Even when you tack on the 4 hour group ride on the weekend, you are still not up to one day's work for a bike messenger.
Yes, yes. Does "law of diminishing returns" mean anything to you?

[sbhikes]

If you are going 5 mph the width of a door is maybe 5 inches. If you are going 25 the width of a door is more like 6 feet. I don't mean the literal width of the door. I mean you need more room when you are going faster, both because it is uncomfortable at high speed to pass things closely and also because you have less time to react. The actual width is not really that important, except as a baseline.

[Helmet Head]

If you are going 5 mph the width of a door is maybe 5 inches. If you are going 25 the width of a door is more like 6 feet. I don't mean the literal width of the door. I mean you need more room when you are going faster, both because it is uncomfortable at high speed to pass things closely and also because you have less time to react. The actual width is not really that important, except as a baseline.
I don't get it. What does cyclist speed have to do with how wide the space is that the car door opens into?

[sbhikes]

It has a lot to do with it. The faster you are going, the further away from stationary objects you want to be. The slower you go, the less important it is. When you go slow you have more time to see things happening in time to react.

I can't believe you need this explained. I guess you don't get out much.

[Brian Ratliff]

HH: Why would the "law of diminishing returns" have anything to do with gaining experience? I'm not sure I'm following you here. Is this from personal experience? Do you suffer from diminishing returns as you gain more experience at a task?

Okay, enough of this. 4-5 feet. 'nuff said.

[sggoodri]

It has a lot to do with it. The faster you are going, the further away from stationary objects you want to be. The slower you go, the less important it is. When you go slow you have more time to see things happening in time to react.

I have to agree with Diane on this one. Creeping uphill, I ride closer to where the edges of open doors will be than when I am cycling downhill, when I am usually near the center of the right travel lane or at least outside a striped bike lane if present.

Downhill, I need a lot more distance to stop. There are a lot more parked car doors in that stopping distance than in my stopping distance when climbing, and the consequences of collision far worse. Thus, I am far less worried about dooring when climbing at under 10 mph than when descending.

Unfortunately, most cities that stripe door zone bike lanes make the uphill and downhill sections equally bad. Cary recently installed a door zone lane on a downhill section of Lake Pine where I am usually going 25-30 in a 35 zone.

[genec]

I have to agree with Diane on this one. Creeping uphill, I ride closer to where the edges of open doors will be than when I am cycling downhill, when I am usually near the center of the right travel lane or at least outside a striped bike lane if present.

Downhill, I need a lot more distance to stop. There are a lot more parked car doors in that stopping distance than in my stopping distance when climbing, and the consequences of collision far worse. Thus, I am far less worried about dooring when climbing at under 10 mph than when descending.

Unfortunately, most cities that stripe door zone bike lanes make the uphill and downhill sections equally bad. Cary recently installed a door zone lane on a downhill section of Lake Pine where I am usually going 25-30 in a 35 zone.

Tend to agree... when I am moving at 4-6 MPH up a steep hill... while I might be thrown into traffic by an opening door, I also have far more time to evaluate the approaching situation, to determine if someone may be in a car, ready to swing that door open... so I too tend to ride closer when going quite slow. That is "closer" not "close," I still give all parked cars a wide berth as sometimes motorists just drive right off from a parking space without looking.

On the other hand, I was also quite surprised by a swinging door (I was well outside of range) once when a sleeping student near UCSD suddenly flung the door open and jumped out to go, no doubt, to a late class. This was well off campus, but the frequency of parked cars co-incided with the semester, so it was obvious that students were using this curb to avoid parking fees.

[Helmet Head]

I have to agree with Diane on this one. Creeping uphill, I ride closer to where the edges of open doors will be than when I am cycling downhill, when I am usually near the center of the right travel lane or at least outside a striped bike lane if present.

Downhill, I need a lot more distance to stop. There are a lot more parked car doors in that stopping distance than in my stopping distance when climbing, and the consequences of collision far worse. Thus, I am far less worried about dooring when climbing at under 10 mph than when descending.

Unfortunately, most cities that stripe door zone bike lanes make the uphill and downhill sections equally bad. Cary recently installed a door zone lane on a downhill section of Lake Pine where I am usually going 25-30 in a 35 zone. I don't know, 5 feet, which is how far I am from parked cars going slow uphills, is also a lot of space when I'm going 35 downhill. Now, if I'm going 35 downhill, I want to be further out in the lane, but that's for a whole host of reasons that having nothing to do with door widths, or even the presence of parked cars.

[KnhoJ]

I don't get it. What does cyclist speed have to do with how wide the space is that the car door opens into?
It's simple physics. Stopping distance increases with the square of an increase in speed. Double your speed, and it takes twice as long to stop while you're covering twice as much ground, for four times the stopping distance. *
For example:
I've got a hill or two which I'll climb at 3 or 4 mph loaded down with too many groceries, and a car door isn't a surprise at that speed. At those speeds, I really could look inside a parked car and count the loose change under the seat before an opening door is a danger. On the other hand, going downhill at 30 mph I need 100 times as much distance to stop, and from that far away I really would need x-ray vision to see what's going on inside a parked car, and esp besides to know when to hit the brakes that far in advance!


* Yes, we know you Googled it and found out that this is only one part of how braking distance works. The explanation overlooks decision and reaction time. But that's how this works, you asked a simple question and you got a simple answer.

[Helmet Head]

It's simple physics. Stopping distance increases with the square of an increase in speed. Double your speed, and it takes twice as long to stop while you're covering twice as much ground, for four times the stopping distance. *
For example:
I've got a hill or two which I'll climb at 3 or 4 mph loaded down with too many groceries, and a car door isn't a surprise at that speed. At those speeds, I really could look inside a parked car and count the loose change under the seat before an opening door is a danger. On the other hand, going downhill at 30 mph I need 100 times as much distance to stop, and from that far away I really would need x-ray vision to see what's going on inside a parked car, and esp besides to know when to hit the brakes that far in advance!


* Yes, we know you Googled it and found out that this is only one part of how braking distance works. The explanation overlooks decision and reaction time. But that's how this works, you asked a simple question and you got a simple answer. What is the relevance of stopping speed if I'm outside of the door zone? If a door opens, I don't even flinch, much less stop.

And if you're in the door zone, you could already be at a complete stop and still be knocked into traffic by a car door that suddenly opens right next to you.

[The other Inane]

From personal experience, I would say that the width of an open door is at least two inches greater than you expect ... and I have the scar to prove it. I actually thought I rode out of the door zone at all times but was proven wrong the hard way.

At least I broke the door though.

[ignominious]

All this wrangling is a tad silly here and really isn't addressing the motivating factor behind door zones. The size of a door zone is in fact a personal issue, albeit one that is informed greatly from interpolated knowledge and experience. The measurement of a door zone is inversely proportional in size to a person's comfort zone.

HH very evidently is not someone who could be categorised as a risk taker as far as cycling is concerned. As such his comfort zone is quite small and to avoid getting out of it he adheres to a rather more strict ruleset, which he perceives as eminently safe. A cycle courier is by their very nature a different creature and one adhering to HH's ruleset would be unlikely to be successful in their profession. Their comfort zone is rather different in order to balance against timing factors and the need to get paid for what they are doing.

Sadly it would appear that the cultural need to categorise things as either good or bad is clouding arguments. My opinion is that neither position is either good or bad simply on the belief that if you were to conduct a study, I reckon you would find that per mile travelled HH and an experienced courier run a very similar risk of being doored.

Your door zone can be calculated in the following way. First check you are in possession of all of the relevant facts. Then be honest with yourself about your level of skill as a cyclist. Three find the position you find most comfortable for your speed and the character of the environment.

[Helmet Head]

From personal experience, I would say that the width of an open door is at least two inches greater than you expect ... and I have the scar to prove it. I actually thought I rode out of the door zone at all times but was proven wrong the hard way.
This is an incredibly important point.

I think most cyclists, even those who think they are aware of the door zone problem, underestimate it both in terms of size and the relevance of their own speed. I saw someone get doored about 20 feet after he entered the road. He passed the first parked car with no problem, was still going less than 10 mph, and the door of the 2nd car he was about to pass suddenly swung open. He was able to walk away from that one, but, again, if he had been a bit further ahead when it opened, instead of him crashing into it, it would have pushed him into traffic.

Another guy once told me his wife was out of cycling for a while because of an injury from a crash. When he told me what happened (quiet residential street, door of a pickup swings open, and knocked her over), I said I was sorry to hear about that and noted something about how important it is to always stay out of the door zone. He denied that they were riding in the door zone.

In both of the above incidents, I am talking about very experienced "club cyclists" who are also commuters.

But my favorite example of someone experienced who underestimates the dangers of the door zone is Robert Hurst in his book "The Art of Urban Cycling" (1st ed). On pp 112-113 he defines the door zone as "the area within about 3 1/2 to 4 feet of the parked cars". He devotes 2 1/2 pages, pp 115-117 to the topic of "reading parked vehicles", where, on page 116 he advises: "Instead of trying to pick up warnings of impending pull-outs and door openings, just leave a minimum 3 1/2-foot buffer between yourself and any parked cars, much more space if practical, and keep tabs on the little buggers out of the corner of your eye".

Now, this might seem nitpicky, but bare with me. It's even worse than it sounds, because when he says "between yourself and any parked cars", what does he mean? More importantly, how are many readers likely to interpret that? Do me a favor. Right now point at yourself. Jut do it. Humor me. Point at yourself. Now, where are you pointing? Follow the end of your finger until you touch yourself. Now, from that point, measure 3 1/2 feet to your right. That is how far Hurst's words indicate you should be from parked cars. Absurd. Nitpick? Maybe, but if you're going to devote a section in your book on avoiding door zones, I think it's important to emphasize that the safety buffer must start from the outermost edge of your body on the right side, not from something as vague as "yourself". Not to mention that even with that clarification, the buffer should be 5 feet, to be safe.

Which brings me to my final point. When you're riding along it's easy to estimate incorrectly how far you are from parked cars. Which way should the error be? Should you err on the side of caution, or risk?

FIVE FEET. No exceptions.

[joejack951]

Nitpick? Maybe, but if you're going to devote a section in your book on avoiding door zones, I think it's important to emphasize that the safety buffer must start from the outermost edge of your body on the right side, not from something as vague as "yourself". Not to mention that even with that clarification, the buffer should be 5 feet, to be safe.

I'll nitpick further. Make sure the outmost part of your "bicycle/body combo" is no closer than 5 feet to any parked cars. My elbows aren't always further spread than my handlebars (or overstuffed pannier) and a car door which smacks my handlebars/pannier has as much of a chance of throwing me into traffic as does the door hitting my elbow (probably more). There was a recent thread in the commuting forum about a guy being taken down when another cyclist's handlebars hooked his as the passing cyclist overtook him. Different situation but same misjudgement about the real width of the vehicle.

[KnhoJ]

Another component I like to keep in mind when I'm passing parked cars at speed is the blind spots created by them. Especially in a couple of the neighborhoods I ride through! Providing the passing room goes a long way towards not running down kids you wouldn't see until they've walked out from between cars and into view. Dogs and (especially!) cats can run out from between, under, or over parked cars.

[Helmet Head]

I'll nitpick further. Make sure the outmost part of your "bicycle/body combo" is no closer than 5 feet to any parked cars. My elbows aren't always further spread than my handlebars (or overstuffed pannier) and a car door which smacks my handlebars/pannier has as much of a chance of throwing me into traffic as does the door hitting my elbow (probably more). There was a recent thread in the commuting forum about a guy being taken down when another cyclist's handlebars hooked his as the passing cyclist overtook him. Different situation but same misjudgement about the real width of the vehicle. :beer:

Good point.

Keep the outermost part of your "bicycle/body combo" at least (what you estimate in realtime to be) FIVE FEET from parked cars. No exceptions. You should be further out than you probably think you should be.

[2manybikes]

HH is totally correct.

One cannot judge the stopping distance by the speed because you don't know how far you will be from the door when it opens. It's impossible. You may be right on top of it.

Human reaction time and stopping distance of a bike limit your ability to move or stop instantly. The door can easily be too close when it opens. Almost no one seems to understand stopping distances. This is important when following closely with bikes and cars etc. I rarely see a car driver that understands. They follow too close. MPH converters to fps are on line. No one gets it! Use the fps converter to see how far you will travel in the fraction of a second it takes before you even move your hands on the levers. Don't estimate, don't guess, it's all on line. !!

Personal experience does not prove that you can ride closer or anticipate the unseen. What it does do in many cases is impart a feeling of false security because you did not get hit yet. That's just ignorant of reality. You might ride right in the door zone all your life without getting hit. You might get doored tomorrow. We/you don't know the odds by what you see and experience. The only way to make sure it does not happen is to not ride in the door zone period. If you chose to take the unknown risk of getting hit by choosing to ride in the door zone that's one thing, but to say you can anticipate when all the doors will open and how close you are is just plain unrealistic and wrong, period. Messengers choose to ignore the risk deliberately or don't understand the risk. That's up to them to take the risk, it does not mean they can miss every door. It does not mean they know the odds of getting doored.

[Helmet Head]

Another component I like to keep in mind when I'm passing parked cars at speed is the blind spots created by them. Especially in a couple of the neighborhoods I ride through! Providing the passing room goes a long way towards not running down kids you wouldn't see until they've walked out from between cars and into view. Dogs and (especially!) cats can run out from between, under, or over parked cars.
:beer:

Another good point.

To all: Whatever it takes to keep you at least _ F I V E _ F E E T _ from parked cars, please do it.

[Bruce Rosar]

One cannot judge the stopping distance by the speed because you don't know how far you will be from the door when it opens. It's impossible. You may be right on top of it.+1 :)

[KnhoJ]

:beer:

Another good point.

To all: Whatever it takes to keep you at least _ F I V E _ F E E T _ from parked cars, please do it.
That's why I carry a tape measure at all times, and stop to calibrate once every two hours. :D

[Helmet Head]

Personal experience does not prove that you can ride closer or anticipate the unseen. What it does do in many cases is impart a feeling of false security because you did not get hit yet. That's just ignorant of reality. You might ride right in the door zone all your life without getting hit. You might get doored tomorrow. We/you don't know the odds by what you see and experience. The only way to make sure it does not happen is to not ride in the door zone period. If you chose to take the unknown risk of getting hit by choosing to ride in the door zone that's one thing, but to say you can anticipate when all the doors will open and how close you are is just plain unrealistic and wrong, period. Messengers choose to ignore the risk deliberately or don't understand the risk. That's up to them to take the risk, it does not mean they can miss every door. It does not mean they know the odds of getting doored.
:beer: :beer: :beer:

Brian, are you reading this? What do you think?

[Helmet Head]

That's why I carry a tape measure at all times, and stop to calibrate once every two hours. :D
Well, really 4 1/2 feet would probably do it, if you actually measured it. But I find that FIVE FEET is a good round number that even when estimated in realtime while riding keeps cyclists out of the door zone, especially when it's understood that the FIVE FEET is supposed to be between the outermost right edge of your body/bike combo to the parked cars.

[Brian Ratliff]

HH: 4-5 feet.

Other than that, another opinion, another post. I personally think that humans are pretty good at calculating risks, that's kind of what we do. Experience informs those calculations. And couriers have far more experience than the lot of us here on this particular forum. So, I'll take them at their word.

[I-Like-To-Bike]

If you chose to take the unknown risk of getting hit by choosing to ride in the door zone that's one thing, but to say you can anticipate when all the doors will open and how close you are is just plain unrealistic and wrong, period. Messengers choose to ignore the risk deliberately or don't understand the risk. That's up to them to take the risk, it does not mean they can miss every door. It does not mean they know the odds of getting doored.
Of course you are ignoring the potential risks that may be presented by choosing another area to ride in. Perhaps you've never cycled in areas where the only other choices are in the midst of extremely dense motorized moving traffic that has little or no safe passing or easy lane changing opportunities; or the sidewalk. It is easy to say "take the lane" or "never ride in the door zone" when the "expert" ignores that the available alternatives may be worse.