General
Bill Feldman: I think Chapter 2 should be divided up differently. The section "Roadway Improvements" should only cover those elements which relate to the creation of a bicycle compatible roadway, i.e. not a designated facility or bikeway. Elements which relate to designated bicycle facilities or bikeways (signed routes, lanes, or paths) should appear under a separate section entitled "Designated Bicycle Facilities (Bikeways)." "Bicycle Paths" should be a sub-section under this heading, as should "Bicycle Routes" and "Bicycle Lanes."
Rich Nowack: More examples of proper bicycle facility design, including drawings, should be added to the Guide. Examples should include proper drainage grates, railroad crossings, pavement surface type, curb and gutter, wide outside lanes, shoulders, etc.
Ken Buckeye: The potential danger of non-existing or improperly designed curb cuts (as well as their effect in discouraging facility use when absent) is an issue which could be discussed. A description of properly designed curb cuts should be included.
Bill Feldman: There should be more emphasis on the point that improvements for motor vehicles should avoid adverse impacts on bicycling. I've seen too many shoulders converted to climbing lanes, turn lanes, or travel lanes that weren't wide enough for shared use. Perhaps there should be a cautionary note or recommendation that specific TSM type improvements to maximize motor vehicle capacity should make certain to accommodate bicycle traffic (see examples in NJDOT Bicycle Compatible Roadways, figs 21,22).
Rick Knapp: P. 8 Last sentence first paragraph: It is stated that bike path designs depend on many factors, including "the performance capabilities of the bicyclist and the bicycle." Bike paths, no matter where they are located, or what their intended purpose will attract the full range of bicyclist skill and equipment. They should be designed to accommodate the full range of each.
Andy Clarke: Delete "whenever possible" from the 2nd paragraph, 2nd sentence: A community's overall goals for transportation improvements should [whenever possible] include the enhancement of bicycling.
Dan Burden: We need much more background for engineers and planners on the "design bicyclist." In particular it would be helpful to detail such things as the bicyclist profile (ages, abilities, lack of licensing, lack of education), a specific section that details the cyclist's viewing height, and the degree to which visual and auditory information are received or blocked. More detailed information is needed on the bicyclist's stopping sight distance, general braking times and distances, and other control factors. The physics of turning, steering, stability, and control need to be explained more fully.
Steve Yost: Guidelines are presented to help design and construct both roadway improvements and separate paths that accommodate the operating characteristics of "bicycles" as defined in the Guide. It further states here that modifications are necessary for adult tricycles, however, it does not name or state what these modifications should be. Let us not force the design engineer to go search for additional information on adult tricycles here. Some figures and guidelines can be listed or referred to some other portion of the Guide.
Tom Walsh: It may be appropriate to add a section on "bicyclist operating characteristics, which could include the bicyclist width, height, and width when leaning into a curve (the concept of super elevating the bicycle). This section could also talk about the characteristics of adult tricycles, bicycle trailers, HPVs, all-terrain bicycles, and the special considerations they warrant in the design process.
Bill Feldman: Replace "separate paths" with "special facilities" in the 3rd paragraph, 1st sentence: "Guidelines are presented in this chapter to help design and construct both roadway improvements and [separate paths] special facilities.
Roadway Improvements
Bill Feldman: The subsections on Shoulders and Wide Curb Lanes should come first
Sharon Todd: More space and emphasis should be placed on roadway improvements, as these aren't as easy to implement as the space allotted to them indicates. Seven pages of the current Guide cover four different types of road facilities, while 14 pages cover the separate path.
Sharon Todd: Explanations that non-bicycling engineers will understand should be given in the Roadway Improvements section, as highway planning and design people often disagree with this section of the Guide (e.g. bicycle lane striping as shown on page 15).
Dick Unrein: Include section on roadway signing/marking; cover warrants, examples for lanes, shoulders, and shared roadways, type, location, spacing, conditions for hazard warnings.
Diane Bishop: Encourage designers to keep sewer lines and utilities out from the area cyclists are expected to ride. Then, if sewer, etc. are dug up, a long longitudinal patch won't be left in that area.
John Forester: "Because most highways have not been designed with bicycle travel in mind, there are often many ways in which roadways should be improved to more safely accommodate bicycle traffic." Wrong. The intent didn't make any difference, and where bicycle traffic was expected the older designs are typically worse than otherwise. Sure, there are deficient roadways. Define the defects, as elsewhere in the Guide, and get them fixed.
Bill Feldman: There are other specific types of roadway improvements that might be mentioned either under one of the existing sub-sections or in a separate sub-section, e.g. striping to mitigate unavoidable obstructions or to reapportion limited pavement space (see NJDOT Bicycle Compatible Roadways, figs 23, 24, 25, 26)
Andy Clarke: Should there be a "Roadway Improvement" section on intersections in general, not just in relation to bike lanes and bike paths? For example, use of wide median strips allowing cyclists to cross busy roads in two stages is given cursory mention in a later section but is a really useful tool to use at many intersections.
Drainage Grates
Andy Clarke: There's no excuse for putting in wrong drainage grates now. No excuse for not having replaced old ones. Maybe incorporate grates into liability section?
Andy Clarke: Replace "are potential problems" with "can be serious hazards" in the 1st paragraph, 1st sentence: Drainage grate inlets and utility covers [are potential problems] can be serious hazards to bicyclists.
Susan Kavulich: The guide doesn't show any examples of acceptable grates. I understand that in the case of a narrow roadway, Ohio DOT sometimes allows for a wide curb lane by eliminating the gutter and recessing the drains into the curb. If this is an acceptable method, it should be included in the Guide.
Andy Clarke: More stress on adjusting grates and utility covers flush with surface, including after a roadway is resurfaced.
X: More detail needed: how to locate and design bicycle-safe grates.
Rick Knapp: It is stated that "identifying a grate with a pavement marking, as indicated in the MUTCD, would acceptable in most situations,..." After many years experience, we have all had with the associated tort liabilities of unsafe drainage grates, the Guide should probably not offer this as a solution, even on an interim basis.
Railroad Crossings
Tom Walsh: This section provides a very good but generalized discussion of the bicyclist's concern. I think this section could be enhanced by including a figure similar to the one enclosed which would help define an appropriate method of widening the pavement to allow a right-angle crossing of tracks that have an adverse orientation.
Dan Burden: We now have several added markings and warnings, as well as improved techniques for handling railroad crossings. These need to be detailed.
Tom Walsh: There is reference to "flangeway fillers." My understanding is that flangeway fillers and covers are applicable only on tracks that carry slow-moving trains, such as industrial crossings. This might be worth clarification. Reference to "commercially available rubberized crossing materials" could be added to this section since they have broader application and do in fact enhance bicyclist safety.
Pavements
John Forester: This section should be retitled Surface Quality and improved by better wording of all the requirements for surface quality that apply to drainage grates, railroad crossings, rumble strips, pavement surface in general, and put in the Green Book. If these standards might be thought to apply to all roads and paths, then specific exceptions may be allowed for rough-surface facilities that are basically hiking paths or wilderness roads.
Bill Feldman: The subsection "Pavements" should specifically mention the adverse impacts of rumble strips and steel grated bridge decks. There should also be a recommendation (probably under "Pavements") that all curb cuts into unpaved parking areas intersecting streets and driveways should be paved back at least 10 feet from the curb line to minimize the possibility of debris migrating onto or being drawn or washed onto the pavement (see NJDOT Bicycle Compatible Roadways pp 16-17)
Traffic Control Devices
John Forester: Retitle this section Traffic Signals, give more details and relocate to the section of the Green Book that covers traffic signals.
Diane Bishop: The Guide does not emphasize the desirability of having detection loops sensitive to bikes.
Glenn Grigg: This section is good, however it lacks specific suggestions as to how detection of bicycles can be accomplished. I suggest that illustrations be included to re-assure engineers that indeed it can be done. The San Diego report is a good source.
X: Not mentioned: instructions for installation of pavement loops for bicycle detection at traffic lights
Tom Walsh: On page 10, second paragraph under traffic control devices would be the appropriate location to make reference to "conveniently located push buttons" as an alternative to pavement loop detectors for actuating traffic signals.
AASHTO: Insert after 2nd sentence, paragraph 2: "Where practical, the use of pedestrian actuated buttons for bicyclists may be a preferred alternative to the use of detectors."
Andy Clarke: I'd like AASHTO's change to read: "In some situations the use of pedestrian actuated buttons are an alternative to the use of detectors, but should not require bicyclists to dismount or lean too far to reach them."
X: Not mentioned: Appropriate signs, taken from the MUTCD, and appropriate sign height
Shoulders
Bill Feldman: Title should be revised to add the word "paved" as follows: Paved Shoulders
Andy Clarke: 1st paragraph, 1st 2 sentences: delete "Wide curb lanes are usually preferred over shoulders for use by bicyclists. However," from the following: "Wide curb lanes are usually preferred over shoulders for use by bicyclists. However, if it is intended that bicyclists ride on shoulders..."
Andy Clarke: 1st paragraph, 4th sentence: Replace "can be" with "are" in the following: Rumble strips [can be] are a deterrent to bicycling
Curt Yates: Re: "wide curb lanes and bicycle lanes are usually preferred over shoulders for use by bicyclists.": Although perhaps not an outright mistake, this statement is misleading. Aren't there many rural high speed roadways where widened shoulders are the preferred option?
Curt Yates: What about wide lanes on a roadway which has no curb and gutter? It's been our experience that on a given project we might be able to add 4 feet to the total cross section of a roadway -enough to create widened lanes-but not enough to provide two 4 foot shoulders. The AASHTO Guide only discusses wide curb lanes, not wide lanes in general.
Rick Knapp: This section starts by saying that "Wide curb lanes and bicycle lanes are usually preferred over shoulders for use by bicyclists." I realize John Forester and others have advocated wide curb lanes instead of bike lanes for years. However, this sentence makes no sense to me unless it is referring to unpaved shoulders. It would seem to me that the vast majority of bicyclists would prefer - let's say and 8-foot paved shoulder to a 14-foot curb lane, or a 5-foot bike lane. In any case, the sentence is inappropriate.
AASHTO: Revised 2nd sentence, 1st paragraph, deleting the items in brackets and replacing them with those emphasized: "However, if it is intended that bicyclists ride on shoulders, smooth paved shoulder surfaces [must] should be provided [and maintained in a clean and safe condition]." Note: AASHTO shows this last part being deleted but it doesn't appear in the published version; perhaps it is from a previous draft revision. -ed.
Bill Feldman: Revise paragraph 1, 3rd & 4th sentences, deleting the items in brackets and adding those emphasized as follows: "Pavement edge lines [supplement] should be used in place of surface texture in delineating the shoulder from the [motor vehicle] travel lanes. Rumble strips can be a deterrent to bicycling on shoulders and their benefits should be weighed against the probability that bicyclists will ride in the motor vehicle lanes to avoid them."
Bill Feldman: Revise first sentence in second paragraph, deleting the items in brackets and adding those emphasized as follows: Shoulder width should be a minimum of [4 feet] 3 feet adjacent to a standard 12-foot travel lane. Total width of paved shoulder plus travel lane should be at least 15 feet when intended to accommodate bicycle travel. Roads with shoulders less than 4 feet (1.2m) wide normally should not be signed as bikeways.
X: Not mentioned: Criteria (combinations of factors such as lane width, ADT, speed limits, % trucks, sight distance, gradients) to use to determine when the paving of shoulders becomes a reasonable cost/benefit item.
X: Not mentioned: Criteria that determine when a roadway has reached such a level of use that shoulders should not be considered a feasible bicycle alternative, if there are other options.
Susan Kavulich: When the main road surface is concrete and the shoulder is asphalt, there can be a joint between the two surfaces that makes it difficult for the bicyclist to maintain control when moving from one surface to the other. I've noticed this problem on some newly-reconstructed highways in Wisconsin and haven't seen it covered in the Guide.
X: Not mentioned: A bike lane/shoulder may be built on only the upgrade side of a narrow roadway, much like a truck lane, to allow faster traffic to pass by in the regular lane (useful in locations where there is room for additional width on one but not both sides of a road that is winding and hilly
X: Not mentioned: A related explanation stating reasons why extra pavement width on the downgrade of a narrow roadway is less necessary, e.g., sight distance allows a motorist to pass a bicyclist once a hill is crested, speeds of bicycles and motor vehicles are more similar on downgrades, roadway is designed for high speeds, a bicyclist who loses control on the downgrade is in trouble regardless of the pavement width, etc.
Rick Knapp: It is stated that "Rumble strips can be a deterrent to bicycling on shoulders and their benefits should be weighed against the probability that bicyclists will ride in the motor vehicle lanes to avoid them." California's highway design standards prohibit rumble strips on highways where bicyclists are permitted. That should be the national standard.
Steve Yost: I believe some clarity needs to be made when referring to shoulders. If the intent is to differentiate between types of shoulders, then I suggest that an adjective describing what type of shoulder that the text is referring to always preceed the word shoulder, e.g. paved shoulder or grass shoulder.
Sharon Todd: Emphasized phrase added: "Shoulder width should be a minimum of 4 feet when intended to accommodate one-way bicycle travel."
Ken Buckeye: A description of the minimum desirable separation of a detached bike path from the adjacent roadway for both urban and rural sections should be included. Mn/DOT's recommendation calls for a 4 foot separation from the curb in an urban section. In a rural section, the separation should be 20 feet from the edge of the driving lane.
Andy Clarke: Why has AASHTO dropped "must be" provided and altered it to "should"?!
Wide Curb Lanes
Peter Lagerwey: Parking: many Seattle streets only have parking on one side of the street. An issue that comes up from time to time is what side of the street should parking be on to best accommodate bicyclists. Our policy has been to put it on the uphill side with the idea that uphill cyclists are going relatively slow and are less vulnerable to opening car doors. Additionally, cars seldom take up the full eight feet allowed for parking which creates a bit of extra space for cyclists as they pump (and wobble) up a hill.
Rick Knapp: It is not clear what is meant by "...can better accommodate both bicycles and motor vehicles..." Perhaps better than narrow lanes, but probably not better than paved shoulders or bike lanes.
Curt Yates: The AASHTO Guide recommends a right lane "wider than 12 feet" for shared bicycle-motor vehicle use. It then recommends a lane width of 14 feet of usable pavement width. What is the utility of a 13 foot lane, and in what situations might it be adequate? "Usable pavement width" could also be more fully explained; the Guide says that "adjustments" must be made for "drainage grates, parking, and longitudinal ridges" In North Carolina, the standard roadway cross section includes a two-foot concrete gutter on each side of the road-not to be considered as usable pavement width, in our eyes. The wording of the Guide should more explicitly state that the gutter is never to be considered as part of the bicyclist's travel space (even if it does have bicycle-safe grates and a very smooth longitudinal ridge).
Curt Yates: The last sentence in this section about the undesirability of lane widths greater than 14 feet leaves an unclear impression- in North Carolina, a shared-use curb lane of 14 feet plus a 2 foot gutter section creates a total "lane" width of 16 feet. Should we, therefore, anticipate the "undesirable operation of two motor vehicles in one lane" as described in the Guide?
Tom Walsh: The reference to 14 feet should be changed to 15 feet and/or a range of 14 to 16 feet being most desirable for better accommodating both bicycles and motor vehicles in the same lane. An important discussion of recent research on curb lane widths is included in Wilkinson's 1986 research report number FHWA-RD-86/066 (pages 52-66), from which language for the AASHTO Guide might be drawn. Among other things, Wilkinson suggests (p. 58) that the benefits of wide curb lanes ought to be specifically acknowledged in the Green Book.
Curt Yates: The AASHTO Guide and Green Book contradict each other regarding wide curb lanes: AASHTO Guide (p. 11): "Widths greater than 14 feet can encourage the undesirable operation of two motor vehicles in one lane..." The Green Book (p. 122) in describing bicycle improvement measures includes: "Wide outside traffic lanes (15 foot minimum if no shoulder)."
Curt Yates: We would like to see differential lane striping on multi-lane roadways covered. In North Carolina, widened curb lanes are frequently obtained by narrowing inside lanes (e.g. from 12 feet to 11 feet) and adding the extra width to the curb lanes. Official inclusion of this strategy in the Guide would make it less controversial within our Department.
Bill Feldman: In my opinion, Wide Curb Lanes should be 15 feet wide, period. This allows for 14 feet of useable space plus 1 foot of shy distance to the curb face, berm, gutter pan, drop off, or whatever. Usable pavement is not normally all the way from the curb face or edge of pavement because of the tendency to shy away from the curbing or pavement edge and because of the debris which usually accumulates along the pavement edge or near the curb. The MD DOT study suggests 15 feet as optimum pavement width for shared use. Doubling up of motor vehicle traffic in the 15 foot lane was not observed.
Diane Bishop: A study was conducted (reported at ProBike 89) which determined that the best width for curbside lanes is 15 feet, not the 14 feet in the Guide.
Susan Kavulich: I think some clarification is needed. The Guide calls for a maximum of 14 feet of "usable pavement width" for a wide shared-use lane. The AASHTO Green Book calls for a minimum of 15 feet excluding the shoulder. I think the discrepancy may result from the Green Book not accounting for "usable pavement width." There should be consistent standards and language in the two publications.
Jim Clark: I have always felt 15 feet makes more sense for a wide curb lane width. Reason: in the future, a 15-foot wide curb lane can be restriped for a 11-foot motorized lane with a 4-foot bicycle lane.
Curt Yates: widths "greater than 14 feet can encourage the undesirable operation of two motor vehicles in one lane, especially in urban areas, and consideration should be given to striping as a bicycle lane when wider widths exist." This implies that a 15 foot lane could be striped to include a bicycle lane. At least in North Carolina, it might easily be assumed that the bicycle lane would then be 3 feet, since our standard vehicle lane is 12 feet. This would be substandard. This section should be clarified or cross-referenced to "Bicycle Lanes."
AASHTO: the following paragraph is added to the end of the section and was revised by eliminating the items in brackets and adding those emphasized as shown by their Committee: "Restriping to provide wide curb-lanes [can] may also be [accomplished] considered on some existing multi-lane facilities by making the remaining travel lanes and left-turn lanes narrower. This should only be performed after careful review of traffic characteristics along the corridor.