ASCE Human Powered Transportation Committee
Update
APRIL 1999

From: Mac Elliott   mac.elliott@home.com
2530 San Elijo Ave. Cardiff, CA 92007
Tel (and fax on request) 760-944-7324
HPT Website. http://www.ascehpt.homestead.com

April 5, 1999

TO All ASCE Human Powered Transportation Committee (HPT Com) Members & Friends.

 1. Committee met Jan 10 & 11 at TRB Conf, Washington DC. See Website for minutes (to be posted soon) or email David Loutzenheiser (david.loutzenheiser@fta.dot.gov) for a copy.

 2. Problems continue with Milled In, (GROUND-IN), Shoulder Rumble Strips (SRS) in narrower shoulders, (shoulders with less than 4 to 5 feet of remaining smooth pavement after rumble strip is installed).

These SRS can and do destroy cycling on narrow shoulders. Cyclists who must swerve because of wind or to avoid debris may hit divots and lose control. Rough and jarring to bikes, the milled-in SRS are being used instead of rolled-ins because of more accurate placement within the shoulder, better control of rumble geometry, and immediate installation without need for other roadwork to occur. It was hoped these depressions with curved bottoms would be bike friendly, and with their better quality control would provide good solution for narrow shoulders. Such is not the case.

1995 article in Transportation Research Record No. 1502, "Rumble Strips or Not Along Wide Shoulders Designated for Bicycle Traffic?", is part of problem, and needs to be refuted or corrected before it causes more damage. For lack of other standards, DOTs use the article for guidance.

Milled-in SRS commonly use 7 or 8 inch longitudinal cut, circle-segment profile, 3/8" to 1/2" deep, 12" to 16" wide, divot type depressions. Article describes these ground-in divots and recommends their installation, spaced at 12 inches, on almost all shoulders with a statement that, "The remaining 18 inch (smooth pavement) space will be sufficient for riding in as long as kept relatively clear of debris".

(This compares with generally accepted minimums ranging from 4 to 5 or even 6 feet depending on conditions, for remaining widths of smooth shoulder space.)

 HPT Com road tested Arizona divots spaced at 1 ft, 2 ft, 4 ft, and 8 ft on center, hoping increased flat space between divots would help. (See Sept 98 Update, Item 1.) The increased spacing was of very little help. Problem seems to lie in shape of depression. Wheel drops into wide curved shape and is immediately forced up and out again, creating the severe jarring effect.

 In order to ease problem of crossing rumbles, Arizona is considering skip pattern, alternating lengths of milled in rumbles with 12 ft lengths of clear shoulder. Arizona also proposing to reduce strip widths below their present 12 inches, down to 8 or even 5 inches, to increase remaining rideable space. Both proposals will help, but will not reduce jarring action when bike hits divots on narrow shoulders.

 In the face of ongoing loss of cycleable roads, HPT Com would recommend a moratorium on SRS installation where remaining smooth surface would be less than say 5 ft wide, until a more bike-friendly rumble configuration is identified and tested. (e.g. Rolled-in rumbles with 1" to 1-1/4" wide by 1/2" deep by 12" long tractor-tread grooves spaced 9 inches on center can be reasonably bike friendly and also provide car rumble. However, rolled-ins have installation problems. Can such a shape be ground or cut in instead? Is this an optimal shape? Etc.)

If one shape is not best for all shoulders, perhaps a 2 tiered system of SRS would be feasible. One for wide shoulders, (perhaps the present milled-in design). A second one, more bike friendly, for narrower shoulders where bikes are more apt to strike the rumble. (The foregoing suggestion is an effort by HPT Com to minimize the damages of SRS to cycling. It ignores the greater questions of when or where SRS on narrow shoulders are advisable at all)

 2a. June 98 issue of "Traffic Report" noted NASA grant to Jeffrey Bishop of Future of Technology & Health Co in Iowa, to develop camera to warn of driver falling asleep. Would be mounted on visor or windshield.and sound alarm if eyelids drooped for too long. Could help road runoff problem as well as other sleep caused accidents.

 3. Roundabouts: Kittleson & Assoc of Portland OR, Bruce Robinson, Principal Investigator, is preparing a Roundabout Guide for FHWA. A draft incorporating results of responses to their Jan 99 Draft is expected by FHWA Apr 19, 1999. HPT Com participated in Jan 99 review.

Point made by speakers at Jan TRB conference was if motorist speeds thru roundabout are 15 mph or less, cyclist safety usually OK. When motorist speeds thru roundabout exceeded 20 mph, cyclist safety in roundabout could be much less than in "standard" intersection. Speeds are controlled by narrowness and sharpness of radii of entry & exit.  (Particularly important to reduce speeds at exits, since cyclists crossing exits may be hit by overtaking exiting vehicles who may assume that cyclist will also exit.) British and Australian roundabouts tend to emphasize Capacity, and increase speed. German, Polish, and Dutch roundabouts emphasize Safety, and reduce speed. See also HPT Com Updates Sep 98, Feb/Mar 98, & Dec97/Jan 98. (Note: "Roundabout" here used, refers to circular intersections with central islands, and with triangular splitter islands to channelize entering and exiting traffic.)

 3a. Werner Brilon sent letter on German Roundabout practice. Some points follow: 1} Cycle lanes in outer part of circular roadway are the most dangerous, and should be forbidden. 2) Mixing bikes with other rural traffic OK if car traffic speeds are reasonable. Cyclists uncomfortable with mixing should be allowed to use pedestrian crossings.

3) Separate cycle paths outside the roundabout are useful when trafficis heavy. (8,000 per day in Netherlands, 15,000 per day in Germany).

4) The foregoing applies to single lane roundabouts only. Multi-lane roundabouts should be free of cyclists. At the least, 2-lane exits must be avoided if cyclists are allowed. Contact Elliott for copy of letter.

 4. FHWA College Bike/Ped Course Book due out this summer. Contact Carol Tan Esse for info. 703-285-2071, carol.tan.esse@fhwa.dot.gov  

4a. Several speakers at Jan 99 TRB meeting emphasized importance of HPT education in schools. John Fegan, FHWA, stated student interest is there. Michael Trentacoste, FHWA, spoke of gaining the toolkit.  Michael Meyer, Georgia Tech, noted transp history started with HPT, and the advantages of using HPT as a means of illustrating basic concepts of transp such as levels of service in all modes, etc. Also the linkage between education and research, and the myriad possibilities of HPT design projects on campus.

(Opportunities still exist for students or professors to take part in various HPT research and info projects. (See Mar 98 HPT Com Update). Contact David Loutzenheiser per Item 8 below.)

 5. Jan 99 Update of Bike Helmet Safety Institute (BSI), notes trends towards more and larger air vents. Larger vents mean less contact area to spread force of blow. BSI felt normal venting in good helmets of mid-'90s was adequate for most riders in most conditions, and should not be increased for general use. '99 also sees continuation of squared off edges and of the elongated aero shape, plus addition of sharp exterior lines, all safety negatives. BFI believes departures from bowling-ball shape increase tendency for helmets to "stick" to surface when they hit, increasing impact intensity or jerking rider's neck. Aero tails can also shove helmets aside as one hits, exposing the bare head. Shape effects are not tested for by current bike helmet standards. Helmets met minimums of ASTM std. Any mfrd after Mar 99 MUST meet new CPSC std (more stringent). None of the new hyper-ventilated models was certified to Snell's B-95 std.

 6. Items from Pro Bike News:

a) Jan 99 PB News. 1998 Univ. of Adelaide study found risk of involvement in urban casualty crash doubled with each 3 mph increase in free traveling speed above 37 mph. 3 mph above 37 mph gave same risk increase as driving with blood alcohol 0.05. Contact BFA 202/463-6622 for order info, or <.raru.adelaide.edu.au/speed>

 b) Aug 98 PB News covers Denver's good experience with Inverted U bike racks, plus its new bike parking ordinance (requires bike parking to equal 5% or car parking), plus a report on bike parking practices worldwide. Contact Elliott for copy, or James Mackay, Denver Bicycle Planner. at 303-640-2453 or Mackayjd@ce.denver.co.us

 7. Next TEA-21 Bike/Ped Design Guidance meeting is scheduled by FHWA for 10:30 AM, Apr 30 in US DOT headquarters bldg. (See Sep 98 HPT Update Item 6). Contact John Fegan, 202-366-5007 for info. 

8. New address for HPT Com Chair David Loutzenheiser: David R. Loutzenheiser, General Engineer. Federal Transit Administration 55 Broadway, Suite 920, Cambridge, MA 02142-1093. (617) 494-2397. david.loutzenheiser@fta.dot.gov fax (617) 494-2865

 9. Elliott has copy of 1998 Transportation Research Record No 1636, "Bicycle & Ped Research" Contents as follows. (Contact Elliott for copy of article(s)..
"Adult Bicyclist in U.S., Characteristics & Riding Experience in 1996"
**"Development of Bike Compatibility Index" (See Item below)
"Research Design Insights from Survey of Urban Bike Commuters"
"Operational Analysis of Uninterrupted Bike Facilities"
"Prediction & Measurement of Travel Time Along Ped Routes"
"Flow Characteristics on Shared Hiking/Biking/Jogging Trails"
"Simplified Estimation of Demand for Nonmotorized Trails Using GIS"
"Development of Bike Path Mngmt System for Univ of Ill @ Urbana"
"Measuring Safety Effect of Raised Bike Crossings Using New Methodology"
"Sidewalk Biking Safety Issues"
"Signal Coordination Benefits for Peds"
"Scramble & Crosswalk Signal Timing"
" Ped Compliance Effects on Signal Timing"
"Use of Signs & Symbols to Increase Efficacy of Ped-Activated Beacons atCrosswalks"
"Passive Ped Detection at Unsignalized Crossings"
"Info Used by Visually Impaired People While Walking"
"Method Estimating Effect of Traffic Vol & Speed.on Ped Safety at Residential Streets"
"Analysis of Ped Behavior & Plan'g Guidelines, Mixed Traffic for Narrow Urban Streets"
"Ultraviolet Headlamp Tchnology, Nighttime Enhancement of Rdway Markings & Peds"
"Child Ped-Car Crashes Near Schools, Small % of Total Child Ped Crashes in Philadelpia"
"Descriptive Analysis of Crashes Involving Peds in Florida 1990-94"
"Let People be Heard,- San Diego County Bike Attitude & Use Survey".

 **10. Bicycle Compatibility Index (BCI) expands on work of Sorton, Walsh, Davis, & others regarding roadway compatibility with bikes. Results detailed in FHWA document, "The Bicycle Compatibility Index, A Level of Service Concept, Implementation Manual", (FHWA-RD-98-095). The "Final Report", (FHWA-RD-98-72) documents the entire research project. Excel workbooks of the BCI can be downloaded from
www.tfhrc.gov/safety/pedbike/research/current.htm
Can contact Carol Tan Esse for Manual or Final Report, (see Item 4 for address).

Mac Elliott