BARF - Bay Area Riders Forum

Go Back   BARF - Bay Area Riders Forum > Moto > 1Rider


Notices

Reply
 
Thread Tools Display Modes
Old 08-12-2019, 03:52 PM   #31
budman
General Menace
 
budman's Avatar
 
AMA Life Member #203453
Highway Aviator
Founding Member
Top Percent Poster
Community Contributor + BB
Moto Junkie

Join Date: Apr 2002
Location: Palo Alto, Ca.
Motorcycles: Keep me rocking life
Name: Budman
Really interesting stuff on the comparison to the 70's and on the types of bikes crashing. HD's are way up there. My mind wonders how many of those involved alcohol.

I am always shocked by the amount of riders going off the road.

The different application of why that happens would be interesting to know. Hit an object seems straight forward. Rock, debris, gravel an object?? Alcohol there would be interesting too.

Thanks Dan.
budman is offline   Reply With Quote
Old 08-12-2019, 04:08 PM   #32
DataDan
Mama says he's bona fide
 
DataDan's Avatar
 
BARF Mod Alumni
BARFie winner 2010 & 2014
Contributor ++++

Join Date: Feb 2003
Location: San Luis Obispo
Motorcycles: Yamaha FJR1300
Name: Dan
Quote:
Originally Posted by budman View Post
HD's are way up there. My mind wonders how many of those involved alcohol.
Among riders in fatal crashes, 35% on Harleys were reported to be drinking, 26% for non-Harleys.
__________________
How can I help seeing what is in front of my eyes? Two and two are four.
--Winston Smith

I see four lights!
--Jean Luc Picard

A is A.
--John Galt
DataDan is offline   Reply With Quote
Old 08-12-2019, 04:16 PM   #33
budman
General Menace
 
budman's Avatar
 
AMA Life Member #203453
Highway Aviator
Founding Member
Top Percent Poster
Community Contributor + BB
Moto Junkie

Join Date: Apr 2002
Location: Palo Alto, Ca.
Motorcycles: Keep me rocking life
Name: Budman
That is pretty high for both. Drinking and driving is bad. Drinking and riding is just a really bad idea period.
budman is offline   Reply With Quote
Old 08-12-2019, 05:34 PM   #34
DataDan
Mama says he's bona fide
 
DataDan's Avatar
 
BARF Mod Alumni
BARFie winner 2010 & 2014
Contributor ++++

Join Date: Feb 2003
Location: San Luis Obispo
Motorcycles: Yamaha FJR1300
Name: Dan
Of the 343 riders in fatal crashes, 97 or 28% were reported to have been drinking. This is based on a blood test, if available, or the investigating officer's subjective assessment. Here's how alcohol use breaks down by age:

__________________
How can I help seeing what is in front of my eyes? Two and two are four.
--Winston Smith

I see four lights!
--Jean Luc Picard

A is A.
--John Galt
DataDan is offline   Reply With Quote
Old 08-14-2019, 08:17 AM   #35
DataDan
Mama says he's bona fide
 
DataDan's Avatar
 
BARF Mod Alumni
BARFie winner 2010 & 2014
Contributor ++++

Join Date: Feb 2003
Location: San Luis Obispo
Motorcycles: Yamaha FJR1300
Name: Dan
Non-motorists killed in motorcycle crashes

In the Bay Area 2013-2017, seven non-motorists were killed in motorcycle crashes. I am including only those killed by a motorcycle, not those killed by another vehicle in a crash that also involved a motorcycle.

cityvictimmc at fault?
--------------------------------------------------------
Oaklandbicyclistno
San FranciscopedestrianDUI
San Franciscopedestrianspeed
San FranciscopedestrianDUI
San Franciscopedestrianno
San Josepedestrianno
Santa Rosapedestrianno
__________________
How can I help seeing what is in front of my eyes? Two and two are four.
--Winston Smith

I see four lights!
--Jean Luc Picard

A is A.
--John Galt
DataDan is offline   Reply With Quote
Old 08-14-2019, 09:29 AM   #36
DataDan
Mama says he's bona fide
 
DataDan's Avatar
 
BARF Mod Alumni
BARFie winner 2010 & 2014
Contributor ++++

Join Date: Feb 2003
Location: San Luis Obispo
Motorcycles: Yamaha FJR1300
Name: Dan
Lane-splitting deaths

There were 13 fatal lane-splitting crashes in the Bay Area 2013-2017. I identified them from news stories that quote a CHP officer or press release (none in this group were in the jurisdiction of another agency). Lane-splitting might be mentioned in a news story unsourced or by a 911 caller via the CAD log, but that is not sufficient to make this list.


Bay Area Lane-Splitting Fatalities 2013-2017 by Roadway

roadway/countycount
--------------------------------------------
US-101 Santa Clara5
I-880 Alameda2
US-101 Marin1
US-101 San Mateo1
US-101 Sonoma1
I-80 Solano1
Altamont Pass Rd1
San Tomas Expressway1


Bay Area Lane-Splitting Fatalities 2013-2017 by Traffic Speed

traffic speedcount
--------------------------------------------
< 203
20-494
50-643
65+3


Bay Area Lane-Splitting Fatalities 2013-2017 by Speed Differential

In 3 cases motorcycle speed was not reported, so differential could not be calculated. In all 3, traffic speed was 55 or higher. In 2, unsafe motorcycle speed was cited as the cause of the crash, and in the third it was rider DUI with speed as a contributing factor.

speed differentialcount
--------------------------------------------
<= 155
16-242
25+3


Bay Area Lane-Splitting Fatalities 2013-2017 by Other-Vehicle Pre-Crash Movement

other vehicle pre-crashcount
--------------------------------------------
going straight9
slowing or stopped2
changing lanes2


Bay Area Lane-Splitting Fatalities 2013-2017 by Type of Crash

"Loss of control" is an overturn, most likely a crash under braking.

type of crashcount
--------------------------------------------
sideswipe5
rear-end5
loss of control3


Bay Area Lane-Splitting Fatalities 2013-2017 by Fault

motorcycle at fault?count
--------------------------------------------
speed5
improper passing3
DUI3
unsafe lane change1
not at fault1
__________________
How can I help seeing what is in front of my eyes? Two and two are four.
--Winston Smith

I see four lights!
--Jean Luc Picard

A is A.
--John Galt

Last edited by DataDan; 10-13-2019 at 09:51 AM..
DataDan is offline   Reply With Quote
Old 08-19-2019, 09:29 AM   #37
DataDan
Mama says he's bona fide
 
DataDan's Avatar
 
BARF Mod Alumni
BARFie winner 2010 & 2014
Contributor ++++

Join Date: Feb 2003
Location: San Luis Obispo
Motorcycles: Yamaha FJR1300
Name: Dan
Backroad crashes

In this thread I have reported on crashes by roadway type--city streets, freeways, rural--but the "rural" distinction didn't capture what I had hoped, the sport-riding environment. Instead, most of those 3000 crashes occurred on non-freeway commuter arteries and unincorporated city streets.

To identify sport-riding roads, I went through road names in the "rural" group, flagged candidates, and, if unfamiliar to me, checked them out in Google Earth. Selecting those with a minimum of 5 crashes in 5 years, I came up with 38 roads and a total of 954 crashes. To some extent, selection reflects my personal preference--roads where the demand is on cornering skill and where the fun happens well under triple digits. Here's is the top of the list, representing 64% of backroad crashes:

Bay Area Sport-Riding Road Crashes 2013-2017

areacrashes
--------------------------------------
SR-1160
Lake Berryessa131
SR-9128
SR-8484
Redwood Rd64
Mines Rd42
  
total609

  • SR-1 here is Marin and Sonoma Counties only; the Santa Cruz and San Mateo parts are not in the 38 roads.

  • Lake Berryessa includes several Napa County roads near the lake: SR-121 between the Napa city limit and SR-128; SR-128 between Silverado Trail and the Solano County line; Berryessa Knoxville Road; Chiles Pope Valley Road; Pope Canyon Road; Butts Canyon Road.

  • SR-9 from Santa Cruz to Saratoga.

  • SR-84 from the coast to Skyline (Niles Canyon is part of the 954 crashes but in a smaller Alameda County group).

  • Redwood Road between Castro Valley and the Oakland city limit.

  • Mines Road includes SR-130 between the San Jose city limit and the observatory.

In upcoming posts I will explore single- vs. multiple-vehicle crashes, lethality, type of crash, and primary factors--similar to the city and freeway crash posts.
__________________
How can I help seeing what is in front of my eyes? Two and two are four.
--Winston Smith

I see four lights!
--Jean Luc Picard

A is A.
--John Galt
DataDan is offline   Reply With Quote
Old 08-23-2019, 10:17 AM   #38
DataDan
Mama says he's bona fide
 
DataDan's Avatar
 
BARF Mod Alumni
BARFie winner 2010 & 2014
Contributor ++++

Join Date: Feb 2003
Location: San Luis Obispo
Motorcycles: Yamaha FJR1300
Name: Dan
Backroad fatalities

While the 954 Bay Area backroad crashes I have identified 2013-2017 (see previous post) were a small part of the region's 16,000 motorcycle crashes, they were a larger contributor to motorcyclist fatalities--33 of 327. This is mainly because a multiple-vehicle crash on a backroad was much more likely to claim a life than on a city street or freeway. Another vehicle was involved in 43% of all backroad crashes but 64% of fatalities.




Lethality--the percentage of crashes resulting in death--was 2.2% for solo incidents but much greater, 5.1%, for multi-vehicle.




Compare single- and multiple-vehicle lethality among city streets, freeways, and backroads:

__________________
How can I help seeing what is in front of my eyes? Two and two are four.
--Winston Smith

I see four lights!
--Jean Luc Picard

A is A.
--John Galt

Last edited by DataDan; 08-23-2019 at 10:30 AM..
DataDan is offline   Reply With Quote
Old 08-26-2019, 11:42 AM   #39
DataDan
Mama says he's bona fide
 
DataDan's Avatar
 
BARF Mod Alumni
BARFie winner 2010 & 2014
Contributor ++++

Join Date: Feb 2003
Location: San Luis Obispo
Motorcycles: Yamaha FJR1300
Name: Dan
Types of backroad crashes

Of the 954 backroad crashes I identified, 546 or 57% were single-vehicle.




The motorcyclist was found to be at-fault in all but a few single-vehicle crashes and in 56% of the multiple-vehicle crashes:




Primary factor in the single-vehicle crashes:




Collision type in the multiple-vehicle crashes where the rider was at fault:



In "over centerline" incidents, the motorcycle crossed the centerline either in a curve or while passing and hit an oncoming vehicle. In "passer vs passee" the rider hit a vehicle turning left while attempting to pass it. In "rear end" the motorcycle struck the vehicle ahead. "OV left turn" includes incidents where the motorcyclist was found to be at fault in a crash with a left-turner either oncoming or crossing from the right, most often due to excessive speed. In "overturn" the motorcycle crashed on its own but incidentally hit another vehicle.


Collision type in multiple-vehicle crashes where the other driver was at fault:



"Left turn etc" is mostly left turns, from the oncoming lane or either side, but also includes entering the roadway, U-turns, and right turns. Basically where the driver failed to yield right of way to the motorcyclist. "Over centerline" incidents are like the motorcycle at-faults, but the other driver ran wide in a curve or was passing. "Cutoff" is like the crashes anywhere else--merging into the motorcyclist's lane. Same with "rear-end", but also includes some incidents where the vehicle was stopped in the roadway and unavoidably hit by the motorcycle.
__________________
How can I help seeing what is in front of my eyes? Two and two are four.
--Winston Smith

I see four lights!
--Jean Luc Picard

A is A.
--John Galt
DataDan is offline   Reply With Quote
Old 08-29-2019, 04:30 PM   #40
DataDan
Mama says he's bona fide
 
DataDan's Avatar
 
BARF Mod Alumni
BARFie winner 2010 & 2014
Contributor ++++

Join Date: Feb 2003
Location: San Luis Obispo
Motorcycles: Yamaha FJR1300
Name: Dan
Conclusion

When I started this thread I didn't know where it would go. I had lots of data on Bay Area motorcycle crashes--so much that it didn't cohere into a useful view. But the process of breaking it down this way and that has helped me make sense of it as a motorcyclist trying to learn how crashes happen in order to prevent them.

In this finale, I'm going to present as simply as I can: by roadway environment, the most common kinds of crashes. Most riders are somewhat familiar with the findings of the Hurt Report, and we all know the folklore that has been around forever. But to get very specific: in the context of the San Francisco Bay Area 2013-2017, based on police reports compiled in the CHP's SWITRS database, how do motorcyclists crash? What emerges isn't exactly "everything you know is wrong", but there are some unexpected results.


If you've skimmed this thread, you know that I initially identified three roadway environments: city streets (non-freeways within city limits), freeways, and rural (non-freeways outside of city limits). The "rural" division proved unhelpful. I was trying to capture the sport-riding environment, but instead got two-thirds unincorporated city streets and one-third twisty roads. I eventually did the hard work of identifying the cool ones, and posted about them. Now I have grouped unincorporated city streets previously in "rural" together with the incorporated city streets, collectively calling them all city streets. Sport-riding roads are what remains of the "rural" group. Freeways remain as I originally defined them.

Starting with approximately 16,000 SWITRS crashes, I identified 9300 on city streets (58% of the total), 5700 on freeways (36%), and 1000 on twisty roads (6%). In the sections below, I rank crash types in each environment by frequency of occurrence.

A few explanations about crash type:
  • cutoff: a crash caused by right turn, lane change, merge, or traffic entry into another vehicle's path
  • signal & ROW: failure to obey sign or signal or to yield right of way
  • LOC speed: loss of control due to speed
  • LOC turning: loss of control while turning


City Streets

single/multiplefaulttype%
-----------------------------------------------------------------------------
multiplecarcar left turn20.1%
multiplecarcar cutoff10.7%
singlemcmc LOC speed10.1%
multiplemcmc rear-end7.3%
multiplecarcrossing vehicle6.6%
multiplecarcar rear-end5.6%
multiplemcother5.2%
multiplemcmc signal & ROW4.5%
singlemcmc other4.1%
multiplemcmc speed3.7%
multiplecarcar U-turn3.4%
multiplemcmc passing3.2%
singlemcmc LOC turning2.6%
multiplemcmc cutoff2.4%
multiplecarcar other2.1%
multiplemcmc left turn1.9%

The notorious left-turner is right where expected. Less obvious is the car cutoff. Both the single-vehicle motorcycle loss of control due to speed and the motorcycle rear-ender are easily preventable.

Freeways

single/multiplefaulttype%
-----------------------------------------------------------------------------
multiplecarcar cutoff29.4%
multiplemcmc rear-end22.1%
singlemcmc LOC speed8.0%
multiplecarcar rear-end7.7%
singlemcmc LOC turning7.1%
multiplemcmc speed6.3%
multiplemcmc cutoff3.7%
multiplecarcar other3.0%
singlemcmc other2.5%
multiplemcmc other2.0%
multiplemcmc turning1.8%
multiplemcmc passing1.8%

Maybe more rider education emphasis is needed on preventing freeway cutoffs, the most common freeway crash in the Bay Area. I suspect that many of these are lane-splitting crashes, but that data is not available. The two-second following distance rule can prevent many rear-enders. If you can't maintain that much space cushion, put yourself behind a small vehicle that gives you a good view to traffic ahead.

Backroads

single/multiplefaulttype%
-----------------------------------------------------------------------------
singlemcmc overturn34.6%
singlemcmc hit object18.7%
multiplemcmc over centerline10.0%
multiplecarcar left, right, U-turn7.6%
multiplecarcar over centerline3.9%
multiplemcmc passer vs passee3.9%
multiplemcmc rear-end3.7%
multiplecarcar cutoff3.4%
multiplemcmc other3.0%
multiplecarcar other2.1%
multiplemcmc overturn2.1%
multiplemcmc speed1.8%
multiplecarcar rear-end1.3%

These crashes, a small percentage of the total, are far more likely to be caused by the motorcyclist than those in other roadway environments.
__________________
How can I help seeing what is in front of my eyes? Two and two are four.
--Winston Smith

I see four lights!
--Jean Luc Picard

A is A.
--John Galt

Last edited by DataDan; 08-29-2019 at 04:36 PM..
DataDan is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -8. The time now is 09:18 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.