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  1. #1
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    Recent research release (dry)

    So far I haven't done more than skim this, i'll be reading it more thoroughly when I get home from a dr. appointment (just passing on some information from my father to my doctor, nothing to worry about)
    I'm sure there are some people and advocates who might want the data and statistics in it who might not be on the TRB lists.

    http://www.trb.org/news/blurb_detail.asp?id=8960

    A Guide for Reducing Collisions Involving Bicycles

    TRB's National Cooperative Highway Research Program (NCHRP) Report 500, Vol. 18, Guidance for Implementation of the AASHTO Strategic Highway Safety Plan: A Guide for Reducing Collisions Involving Bicycles provides strategies that can be employed to reduce collisions involving bicycles....
    Current stable: Sun Atlas X-type (mine), Trek Navigator 3 (wife), two Sun Revolution cruisers (wife, daughter)

  2. #2
    Part-time epistemologist invisiblehand's Avatar
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    Thanks.

    177 pages ... at least that includes pictures.

  3. #3
    genec genec's Avatar
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    For all of you that think I whine too much about high speed roads... Take a gander at this:

    Quote Originally Posted by the report
    Traffic Speed
    Speed influences both the severity of crashes that occur as well as the likelihood of
    occurrence, and has been identified as a contributing factor in all types of crashes. National
    data suggest that 31 percent of crashes were speed-related. Driving too fast for conditions or
    in excess of posted speed limit or racing was identified as a contributing factor for drivers in
    30 percent of all fatal crashes in 2005 (NHTSA, 2005 data). Fatality rates are also higher for
    crashes on higher speed limit roadways, climbing from about 2 per 1,000 crashes at speeds of
    48 km/h (30 mph) or less to more than 14 per 1,000 at 88 km/h (55 mph) or more.
    Fatal
    bicyclist injuries were more than six times as prevalent, and disabling injuries were nearly
    twice as prevalent, than for all bicyclist crashes in North Carolina when excessive speed was
    indicated. Bicyclists are vulnerable road users, and the impact of higher speeds on crash
    severity is obvious.

  4. #4
    genec genec's Avatar
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    Here the report address yet another pet peeve of mine...
    Quote Originally Posted by the report
    Throughout the United States motorists are permitted to make a right turn on red (RTOR)
    movement unless prohibited by a posted traffic sign. The only exception to this rule is within
    New York City, where RTOR is generally prohibited unless otherwise permitted at specific
    locations by posted traffic signs. State RTOR laws generally require that drivers come to a
    complete stop and yield to approaching traffic before making a RTOR maneuver. The national
    policy permitting RTOR was instituted primarily to reduce fuel consumption following the
    energy crisis of 1973. Additional benefits of the RTOR policy include reduced vehicle delays
    and tailpipe emissions (Retting et al., 2002).

    Following the adoption of the national RTOR policy, significant increases in bicycle crashes at
    signalized intersections were reported (Preusser et al., 1982; Zador, 1984).
    The effects were
    more pronounced in urban and suburban areas than in rural areas that have fewer signalized
    intersections (Preusser et al., 1982). Preusser et al. (1982) also reported that in most cases
    bicyclists were approaching from the driver’s right side and drivers frequently claimed they
    were looking to the left searching for a gap in traffic and never saw the bicyclists.
    The primary purpose of this strategy is not to restrict RTOR at all signalized intersections in
    an area or local jurisdiction. Rather, the purpose is to restrict RTOR movements at certain
    signalized intersections throughout the entire day or during portions of the day (e.g., during
    periods of peak bicycle activity). At signalized intersections with a history of bicycle/motor
    vehicle crashes resulting from RTOR movements, an analysis of the time of day of the crashes
    may provide justification for restricting RTOR movements throughout the entire day or
    during specified hours of the day.

  5. #5
    Sumanitu taka owaci LittleBigMan's Avatar
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    Following the adoption of the national RTOR policy, significant increases in bicycle crashes at
    signalized intersections were reported (Preusser et al., 1982; Zador, 1984). The effects were
    more pronounced in urban and suburban areas than in rural areas that have fewer signalized
    intersections (Preusser et al., 1982). Preusser et al. (1982) also reported that in most cases
    bicyclists were approaching from the driver’s right side and drivers frequently claimed they
    were looking to the left searching for a gap in traffic and never saw the bicyclists.



    This concerns me as a pedestrian because in order to get a good view of approaching traffic, the driver often must creep forward, blocking the crosswalk. In addition, the driver is looking to the left, and if I'm approaching on foot from the right, he might not look at me. As a pedestrian, this interferes with my right-of-way when using a crosswalk on a green signal.

    However, a cyclist approaching a driver from the right who is making a right turn on red would have to be riding against traffic, or on the sidewalk, to be in conflict with the driver's turn. A cyclist in proper lane position will not conflict with the ROTR driver from the "blind" side. I wonder why this factor (riding a bicycle against traffic) was not mentioned as a contributory factor in bicycle/car crashes involving ROTR's.
    Last edited by LittleBigMan; 04-29-08 at 01:16 PM.
    No worries

  6. #6
    genec genec's Avatar
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    Quote Originally Posted by LittleBigMan View Post
    Following the adoption of the national RTOR policy, significant increases in bicycle crashes at
    signalized intersections were reported (Preusser et al., 1982; Zador, 1984). The effects were
    more pronounced in urban and suburban areas than in rural areas that have fewer signalized
    intersections (Preusser et al., 1982). Preusser et al. (1982) also reported that in most cases
    bicyclists were approaching from the driverís right side and drivers frequently claimed they
    were looking to the left searching for a gap in traffic and never saw the bicyclists.



    This concerns me as a pedestrian because in order to get a good view of approaching traffic, the driver often must creep forward, blocking the crosswalk. In addition, the driver is looking to the left, and if I'm approaching on foot from the right, he might not look at me. As a pedestrian, this interferes with my right-of-way when using a crosswalk on a green signal.

    However, a cyclist approaching a driver from the right who is making a right turn on red would have to be riding against traffic, or on the sidewalk. A cyclist in proper lane position will not conflict with the ROTR driver from the "blind" side. I wonder why this factor (riding a bicycle against traffic) was not mentioned as a contributory factor in bicycle/car crashes involving ROTR's.
    Wrong way riding may not be the only situation... I for one have seen far too many motorists not pause long enough to get a good look before they set out, or worse the following motorist doesn't even stop.

    While RTOR works in theory, the actual practice of it is usually right turn... no stop, thus motorists are not taking the time to see something as narrow as a bike, especially if the cyclist is moving at the speed of traffic and blends in to that moving picture.

  7. #7
    -=Barry=- The Human Car's Avatar
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    I'll strongly assert that RTOR has failed to accomplish anything beneficial for society.

    Reduce fuel consumption - by encouraging jack rabbit accelerations???
    Reduced vehicle delays and tailpipe emission - for one intersection sure but the net effect of having the whole traffic grid set up this way with constant traffic diarrhea over pulsated traffic platoons has made minor street and business drives (without lights) an increasingly hazardous and undesirable thing to leave the traffic sewer. Which places vulnerable road users more at risk both at major an minor intersections. It has placed a economic harm on small local business that can't get dedicated traffic light for their business and has provided an economic benefit for major box stores by government suppling them an easer to use access even though it encourages more miles to be be driven y people to get to these mega easy to access box stores. It is just fact, people are driving more miles to do the same things they have always done and this in no way reduces tail pipe emissions.

    I think the problems created by RTOR are almost identical in logic to problems created by poor storm water management. The benefit of eliminating delays for water to get from here to the river is local and poor storm water management generally only causes a problem for someone else downstream. With poor storm water management we call the problem "flooding" with over accommodating the flow of traffic we call the problem "congestion" while generally over 90% of our road network is congestion free.
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  8. #8
    -=Barry=- The Human Car's Avatar
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    Quote Originally Posted by LittleBigMan View Post
    However, a cyclist approaching a driver from the right who is making a right turn on red would have to be riding against traffic, or on the sidewalk, to be in conflict with the driver's turn. A cyclist in proper lane position will not conflict with the ROTR driver from the "blind" side. I wonder why this factor (riding a bicycle against traffic) was not mentioned as a contributory factor in bicycle/car crashes involving ROTR's.
    That's only one scenario, the other is a cyclists pulls up at an intersection and when the light turns green goes and the motorists turning right sees the traffic stop and then goes without "seeing" the cyclist.

    I've seen people try to do this to me from left hand turn lanes and from the wrong side of a double yellow line. The right not to be delayed takes precedences over any other commonsense or safety consideration.
    Last edited by The Human Car; 04-29-08 at 02:11 PM. Reason: spelling
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  9. #9
    genec genec's Avatar
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    Quote Originally Posted by invisiblehand View Post
    Thanks.

    177 pages ... at least that includes pictures.
    About half of that is "how to implement these ideas... " Section V contains the real "meat and potatoes."

    Check it out, it isn't that bad of a read.

    I think the thing I found most interesting is the commentary on "parallel travel accidents" which is stated as being about 35% of all accidents.

    Quote Originally Posted by the report
    As discussed in Section III, 35.5 percent of bicyclist crashes with motor vehicles occur when travel directions are parallel. Roadway facilities that better identify appropriate travel areas for all road users and their expected behavior may provide a safer environment for bicyclist travel along parallel paths and help reduce crashes.
    This is a significant difference from the often touted data mentioned in Effective Cycling and other writings often quoted by strict vehicular cyclists... (and based on studies from the mid '70's)

    *****************************************
    In this section (section V, Objective B) there is also clear acknowledgment of the problem of dooring... and a suggestion for the use of sharrows.

  10. #10
    Senior Member
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    Quote Originally Posted by LittleBigMan View Post
    Following the adoption of the national RTOR policy, significant increases in bicycle crashes at
    signalized intersections were reported (Preusser et al., 1982; Zador, 1984). The effects were
    more pronounced in urban and suburban areas than in rural areas that have fewer signalized
    intersections (Preusser et al., 1982). Preusser et al. (1982) also reported that in most cases
    bicyclists were approaching from the driverís right side and drivers frequently claimed they
    were looking to the left searching for a gap in traffic and never saw the bicyclists.


    However, a cyclist approaching a driver from the right who is making a right turn on red would have to be riding against traffic, or on the sidewalk, to be in conflict with the driver's turn. A cyclist in proper lane position will not conflict with the ROTR driver from the "blind" side. I wonder why this factor (riding a bicycle against traffic) was not mentioned as a contributory factor in bicycle/car crashes involving ROTR's.
    Nope. There are two ways this can happen legally.

    1. The cyclist is traveling parallel to the turning vehicle in a bike lane.

    2. The cyclist is on a sidepath style bike path, traveling with the flow of traffic.

    I suspect you're right, and riding against traffic is the most common cause. But it isn't the only option. I have never run into the first personally, and I hope I never do. I treat any car that even *looks* like they're thinking of turning as a danger, and I stop well to the rear of them. The second is a standard encounter if you ride a sidepath style bike path, even with a pedestrian/path only signal.

  11. #11
    Al noisebeam's Avatar
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    Quote Originally Posted by genec View Post
    I think the thing I found most interesting is the commentary on "parallel travel accidents" which is stated as being about 35% of all accidents.

    This is a significant difference from ...
    Is it? I always thought that hit from behind was touted as rare, but sideswipe not.

    (Just this morning I avoided a sideswipe when I was in BL. My tire track was 12" inside bike lane stripe, I heard a truck coming from behind and glanced in mirror and saw a glass panel truck approaching. The front of the modified pickup truck was fully within the adjacent lane, but the L shaped bracket that supports the glass panels was over the stripe by at least 6". Having little time to signal I did a little swerve to see if the driver would react, but they didn't so I moved far right in the BL and the L bracket passed by my feet with about 18" to spare.)

    Al

  12. #12
    Senior Member wahoonc's Avatar
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    As a cyclist AND driver for over 32 years I have seen a change in traffic. People are more hostile and more selfish. More distractions in the car, cars have been made safer but the drivers have not. My general observation is that US drivers are sloppy, they don't hold the lane, roll stop signs and completely blow red lights. When stopped and confronted by LEO's the first rule is to deny everything, then get a lawyer and dump the ticket. There is also a sizable number that have bought into the attitude that laws are for "other people". Several years ago I was an associate adviser for an Law Enforcement Explorer Post and we got to go on ride alongs. The excuses were pathetic. Also I suspect there is more tolerance for some things like speeding 10mph over when it used to be less.

    I am a firm believer that separate facilities are a requirement, especially on higher speed arterials. If you think motorists have issues with cyclists now, wait until the numbers increase. We also need better education of both cyclists and motorists. I see numerous wrong way riders on a daily basis, some of them are wearing safety vests and even the occasional helmet, but are riding the wrong way on a 4 lane 50+mph roadway.

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  13. #13
    genec genec's Avatar
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    Quote Originally Posted by noisebeam View Post
    Is it? I always thought that hit from behind was touted as rare, but sideswipe not.

    (Just this morning I avoided a sideswipe when I was in BL. My tire track was 12" inside bike lane stripe, I heard a truck coming from behind and glanced in mirror and saw a glass panel truck approaching. The front of the modified pickup truck was fully within the adjacent lane, but the L shaped bracket that supports the glass panels was over the stripe by at least 6". Having little time to signal I did a little swerve to see if the driver would react, but they didn't so I moved far right in the BL and the L bracket passed by my feet with about 18" to spare.)

    Al
    This type have accident, parallel travel, has always been touted as rare and thus BL were often touted as being "frivolous" as they work primarily to curb parallel travel incidents. Sideswiping was usually considered part of this category.

    Intersection accidents were always touted as the most frequently occurring.

  14. #14
    Senior Member
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    Quote Originally Posted by genec View Post
    This type have accident, parallel travel, has always been touted as rare and thus BL were often touted as being "frivolous" as they work primarily to curb parallel travel incidents. Sideswiping was usually considered part of this category.

    Intersection accidents were always touted as the most frequently occurring.
    Gene,

    I think the report is confusing on that point. Notice that a substantial percentage of the 'parallel path' collisions are actually right and left hooks by motorists, or bicyclists turning into motorists' paths. In the end it seems the old Forester claim, that about 90% of all car-bike collisions in urban areas 'involve turning or crossing,' is pretty well supported by this data from the early '90s.

    Robert

  15. #15
    genec genec's Avatar
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    Quote Originally Posted by RobertHurst View Post
    Gene,

    I think the report is confusing on that point. Notice that a substantial percentage of the 'parallel path' collisions are actually right and left hooks by motorists, or bicyclists turning into motorists' paths. In the end it seems the old Forester claim, that about 90% of all car-bike collisions in urban areas 'involve turning or crossing,' is pretty well supported by this data from the early '90s.

    Robert
    OK so technically not true overtaking situations... but indeed the issue of motorists approaching cyclists from behind and then making decisions to make right turns (and right hooks) is still an issue that can be quite easily resolved by the motorist.

    And no, obviously BL will not help in this situation.

  16. #16
    Sumanitu taka owaci LittleBigMan's Avatar
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    Quote Originally Posted by LittleBigMan View Post
    Preusser et al. (1982) also reported that in most cases bicyclists were approaching from the driverís right side and drivers frequently claimed they were looking to the left searching for a gap in traffic and never saw the bicyclists.
    Given this scenario, the cyclists would have to be riding against traffic. Cyclists riding with traffic could not be approaching from the drivers' right-hand side.

    Riding against traffic is unlawful for cyclists, so I wonder why this was not taken into account.
    No worries

  17. #17
    totally louche Bekologist's Avatar
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    I like some of the infrastructure modifications suggested in the report. Raised center safety turn islands at unsignalized intersections piqued my interest. The report was quite forward thinking IMO. I need to give it another readthru., i was skimming for overview, it is a big file..

  18. #18
    52-week commuter DCCommuter's Avatar
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    Quote Originally Posted by LittleBigMan View Post
    Given this scenario, the cyclists would have to be riding against traffic. Cyclists riding with traffic could not be approaching from the drivers' right-hand side.

    Riding against traffic is unlawful for cyclists, so I wonder why this was not taken into account.
    Unless the cyclist is passing on the right. Perfectly legal here, actually specified in the code.
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  19. #19
    52-week commuter DCCommuter's Avatar
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    I find this table on page 14 to be very interesting:

    Similar typology was used in the FHWA study by Hunter et al. (1996). In a six-state study of
    3,000 bicycle crashes taken from hard copy police reports, the most frequent bicycle/motor
    vehicle crash types were as follows:

    Crossing Path Crashes % of All Crashes
    • Motorist failed to yield to bicyclist (includes drive out/through 21.7
    at intersections and at Midblock/driveway locations)
    • Bicyclist failed to yield to motorist at an intersection 16.8
    • Bicyclist failed to yield to motorist, midblock 11.8
    • Other crossing path crashes 7.2

    Parallel Path Crashes
    • Motorist turned or merged into bicyclist’s path 12.2
    • Motorist overtaking bicyclist 8.6
    • Bicyclist turned or merged into motorist’s path 7.3
    • Other parallel path crashes 7.4
    From these numbers, we can do a very crude assignment of fault. If we assume that whoever fails to yield, or merges into someone else's path is at fault, and the overtaking vehicle is at fault in a collision, we get:

    Motorist fault: 21.7+ 12.2 +8.6 = 42.5%
    Cyclist fault: 16.8 +11.8+7.3= 35.9%

    So at a rough level, the motorist is at fault about 20% more of the time than the cyclist.

    Keep in mind that these determinations come from the police reports, and police are notorious for having a car-centric bias when it comes to determining fault. Also, in many car-bike collisions the driver is the only witness, as the cyclist is much more likely to be incapacitated or killed. However, in many car-bike collisions the driver is not a reliable witness because he never saw the cyclist.
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  20. #20
    totally louche Bekologist's Avatar
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    i think the study was also interesting in its' broad based truths about bicycling- bicyclists inherently recognize they are vulnerable road users, and that perceived safety as well as actual safety have an effect on bicycling participation. There's a lot more to that too...



    This is a well prepared and far reaching report; i recommend it to any one interestered in promoting bicycling and improving bicyclist safety in America. (Anyone NOT interested in promoting bicycling in america should reach for a copy of effective cycling.)

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