University Drive textured Bike Lane

[update Jan 2018: the project area has been resurfaced (already? why?) see below]
The project area is University Drive between east of Priest Dr and Farmer Ave [correction: it’s actually Ash, a few hundred feet further east; i did not update the crash history, below; i don’t think it would change much]. There are other aspects of the project I like very much, e.g. the new raised medians. These should make the road safer for all users. The speed limit is still posted at 40mph, I encourage the city to lower the limit to 35mph, which would make the road even safer for everyone.

In a nutshell, the problem is the City placed 2′ of texturing in a 6′ bike lane, leaving only 2.5′ of usable surface (the gutter pan is the remaining 1.5′). I have a photo gallery (or most of same pics on a public facebook album) of some of the issues revolving around the texture in the bike lane.

The usable width is perhaps 2 feet. Photoshop (in blue) credit: Dan Gutierrez

In case it needs to be explained: Besides the texture being uncomfortable to ride on, longitudinal (parallel to the line of travel) cracks, grooves, depressions etc. are anathema to bicyclists because they can create a fall hazard. Most bicyclist injuries occur from “simple” (non-MV crash) falls. ALL Bike Lanes (next to a gutter) already have one longitudinal crack that presents a hazard. Besides being too narrow (the usable surface), I worry about maintenance problems as time goes on with the stamped asphalt deteriorating. See e.g. the massive deterioration on the Warner Road bike lane at Kyrene, or for that matter the Mcclintock Road fake bike lane — these examples are both in City of Tempe, why not fix the existing broken bicycle infrastructure first?

So, I haven’t really been following this, but on Jan 15th Tempe City councilman Kolby Granville posted a pic on his facebook if the finished project; the discussion centered on the textured bike lane. I’ve got to give him credit for listening to concerns and getting questions answered via City of Tempe (presumably, Streets Dept) Staff, e.g.: first alarm bells were this: “Staff considers the stamped concrete part of the bike lane and not a narrowing of the bike lane” and this longer response a little later:

Kolby Granville I know this is not the answer many of you are looking for, but I do want you to know that I read all these comments, forward many to staff, and continue to try and work to improve the way we do this. Here is the response from staff…. I might also add, I disagree with some of this, for example, I think the brick areas should no longer be considered part of the bike lane width. I also think the area along the curb that is concrete, and basically unridable, should not be considered part of the bike lane width. That said, I think this is is a good experiment me are doing, and will (and already has) taught the city valuable lessons for ways to do things better moving forward. ~Kolby
STAFF RESPONSE: 1. “This portion of University Drive had bike lanes added in 1993, previously there were none.
2. The bike lanes prior to this project were 4 – 4 ½ feet wide.
3. We had several large public meetings for this project in 2012 and 2013 with more than 50 attendees at each.
4. Notification for the public meetings was provided by door hanger to all residents and business owners along the street and one half mile north and south of the street. Additionally the city notified organizations like Tempe Bicycle Action Group and ASU to get feedback.
5. We accepted online comments for the duration of the project design and we had several smaller meetings with property owners and businesses along the corridor.
6. The project was presented to the City Council twice and had significant public comment through that process as well.
7. We received strong feedback to explore buffered bike lanes, protected bike lanes, widened bike lanes; generally there was support to make the bike lanes a more visible and important part of our street project.
8. We have heard from much of the community that bike lanes need to accommodate all ages, skill levels and types of riders. So we are not focused solely on a beach cruiser mountain bike, but also on athlete cyclists and fixed gear riders etc..
9. There has been a particular push from the community for bike lanes that feel more comfortable for unskilled and young cyclists, so as to inspire new riders.
10. The new configuration of bike lanes is 6 feet wide comprised of a two foot bike buffer stamped asphalt(bricks), an 18” concrete gutter pan and a 2 ½ foot untreated asphalt segment. All elements of this 6 foot lane are meant to be traversable for all types of cyclists. The car lanes [ed note: the term ‘car lane’ is incorrect; and I would expect transportation professionals not to use it. If it’s important to make the distinction, it should be ‘travel lane’, or ‘general purpose travel lane’] on University Dr were narrowed to an allowable width to make room for this treatment.
11. The new configuration is meant to give higher visibility for the bike lane, through visual and textural treatments. This also includes portions of the lane that are treated with green reflective thermoplastic.
The wider bike lanes [ed note: a normal/nominal BL is 4′ next to a 1.5′ gutter pan = 5.5′. So 6′ isn’t vastly wide] should make it easier than before to have passing opportunity for cyclists, but I would think that a passing cyclist would still need to go into the car lane [ed note: see note above about the term ‘car lane’] and would of definitely needed to do so with the previous narrower bike lane design.
12. We are engaged in implementation of protected bike lanes, buffered bike lanes and higher visibility bike lanes on several projects in Tempe right now. We feel that the innovations we are working on now will lead to some more consistent design treatments city wide that have broad acceptance. We welcome the feedback, like yours, as we determine what is going to work best in the long term.”

There is much there that I don’t agree with, I mean the stuff like: “…bike lanes that feel more comfortable for unskilled and young cyclists, so as to inspire new riders” and similar vein, but I’m not going to try and address it here. The staff-writer has a fair point that this was aired in public so I went to the City’s project page which has many documents. Contrary to the staff-writers claims, I cannot find much if anything about the texturing, in the final design concept” there is this strip that starts and stops several times; but it’s to the left of a normal BL. The notation for the strip says “Separated Bike Lanes Pavers or Stamped Asphalt Strip Separating Bike Lane from Vehicle Lane”. The only special thing about the BL in general  was they were “green bike lanes at intersections for enhanced visibility”.  So where the idea of placing the texturing within the BL came from I still have no idea.

We see lots of interesting factoids there, the “project is funded with $2.2 million in federal Congestion Mitigation & Air Quality grant money” (CMAQ). Yikes.

universityDrawingDetailHere’s a little tidbit from the  construction drawings (66 sheets!) that shows the dimensions of the “stamped asphalt treated bike buffer”; 4′ (from curbface), 2′ of the stamping, plus an 8″ BL stripe. It, oddly, shows the BL marking as being stamped within the gutter pan, which should not be (and apparently was not) done. Also according to the drawings the travel lanes are  10.5′ wide in some areas, and 11.5′ in others (IIRC, the western portion, towards Priest Drive, is wider).


There is a long thread on Cyclists are Drivers f.b. group discussing the project (you need to join the group to see it).

Other “Textured” Bike Lanes

Can’t find much…seems strange. I note there was a similar project done in City of Tucson in 2010 along Mountain Ave with what may be a similar process; see also article. (By the way — I also noticed in that streetview that Tucson often has vertical concrete curbs but no gutter pan — how does that work? I don’t believe I’ve EVER seen that in the Phoenix metro area?) In any event the absence of a gutter seam means this Tucson bike lane has a somewhat wider usable surface; it may even be 4′, just estimating.

MUTCD and other engineering concerns?

I have some doubts about the engineering behind the bike lane (BL). The general notion of BLs is fairly well laid out and it’s certainly properly and nicely marked with symbol markings and regulatory signs. It’s also certainly wide enough (ignoring the texture:  at 6′ from curb / 4.5′ from gutter seam) to accommodate the vast majority of bikes/trikes/trailers; the use of green paint is also clearly OK via what is known in engineering circles as an “Interim Approval”  —  Optional Use of Green Colored Pavement for Bike Lanes (IA-14) from the FHWA. (this FHWA link is handy). The City of Tempe is on the list as IA-14.40 so I imagine they properly requested and received the IA for this project.

I can’t really find anything on the use of texture within a BL, or the extra red/reddish paint for that matter. It seems to me to be a bad idea; in other words, it may not be explicitly prohibited but it just seems so kooky that no prudent engineer would sign off on it. It’s similar to a rumble strip, I mean the concept, which are covered in the MUTCD e.g. see part 3J (rumble strips are prohibited in BLs IIRC); but then it’s not really a rumble strip either.

It seems to me adding these design elements, the red color, and the texturing, to a traffic control device (a Bike lane is a TCD) should have been done only after seeking permission to experiment from the FHWA pursuant to MUTCD Section 1A.10,  afaik that was not done; and if that’s the case, besides being in violation, what we then have is a non-scientific experiment from which no conclusions can or should be drawn; e.g. do these unique design element improve safety?

See below for “Request for Official Interpretation”.

Collision History (#collision)

There were a total of 212 MV collisions of all types reported in the 5 year period 2009-2013 in this area (University; east of Priest, and west of the train tracks). Only 2 were pedestrian-MV; and 21 were bicyclist-MV. (visit crashmap to see crashes for yourself; see the actual query used )

Of the 21 bike-MV collisions (the query used is in this comment):

  • All were “angle” type collisions (there were no rear-end or overtaking).
  • The bicyclist was found Most at Fault (MaF) in ALL of the collisions.  this is rather shocking, statewide average rate is only 52%, Tempe city-wide average is somewhat higher around 60% — but 100%!?
  • wrong-way riding was rampant — the bicyclist appears to have been riding the wrong way (almost always on the sidewalk/crosswalk) in 16 of the 21; and was with traffic in only 3 (two were indeterminate).
  • Injury severity was generally low. There were only 3 incapacitating injuries. All three of those were precisely the same collision: a wrong-way sidewalk cyclist during daylight collided with a right-turning vehicle. The vehicle either had a stop sign, or was emerging from a driveway.
  • Most were in daylight, only 5 were in darkness.

There were numerous coding errors and inconsistencies. The most common was and incorrect JunctionRelation. In one case the motorist’s and bicyclist’s UnitAction appear to be reversed (2595568). There is a tendency to use “OTHER” for bicyclist violation. There were many (too many) UNKNOWNs, NOT_REPORTEDs and NOT_APPLICABLEs.

There was a bicyclist fatality just east of the project area, at University and Ash in 2010; in that case, police say the bicyclist disregarded a signal.

Note there is a rich bike-count dataset courtesy of TBAG 2013. Sidewalk and wrong-way riding is known to be high, e.g. at University and Ash/Hardy/Roosevelt EW it’s  wrong way 12-20%; and sidewalk overall is 24-44%.

I haven’t tried to quantify it, but the count data correlated with the collision history is a vivid example of just how much more dangerous wrong way riding is; i.e. in round numbers only 1 in 5 riders is going the wrong way, but wrong way riders crash over 5 times as often (16:3).

Some Background on the Area

… particularly if you are not familiar with the area. University Drive is a major east-west arterial in the City of Tempe. The road has for many years (perhaps since the 1993, mentioned above) been two-through lanes in each direction. Very major intersection, like for example University and Priest, Mill, Rural have additional widening for extra lanes, maybe dual-left turn only; or a right turn only pocket… but otherwise it’s the two through lanes, either a continuous center lane, or medians with left turn pockets. There are many intersections, many of them signalized, and many driveways. This keeps motorist speeds relatively low, although it seems to be posted 40mph; it seems 35 would be more appropriate; and wouldn’t affect traffic flow or volume at all, because of the many signals and turners; further east on University it is already posted 35. (and Rural Road has more lanes, 3 in each direction, and is posted 35mph).

The bike lanes pre-existing were as far as I can tell/remember/know were “normal” AASHTO guide – compliant, bike lanes, and extend all the way from something like the SR143 on the east to SR101 on the west. This is more-or-less the entire width of the city of Tempe, it’s about 8 miles. Bicyclist access at the freeway interchanges tends to be dicey, and I’m not sure what goes on there.

Arizona State University is on University Drive between about Mill and Rural. The center (the north and south center) of downtown is Mill Ave.

The project area, as mentioned above, is University Dr between around Priest and Ash (in other words, just west of ASU and downtown). The area is heavily influenced by ASU, which is among the largest university campuses (is that word?) in the US with something over 50,000 students.

Requesting an Official Interpretation

On 3/1/2015 I submitted a “request for official interpretation” as outlined here ; I received a reply via email 3/20/2015 (that was quick!):

—– Forwarded Message —–
From: Bruce Friedman
Sent: Friday, March 20, 2015 12:03 PM
Subject: RE: Texture and color within Bicycle Lane

Thank you for your interest in bicycle safety.
We have considered the document that was attached to your March 1st e-mail message and are unable to offer an official interpretation based on the questions that are being asked.

Paragraph 6 of Section 1A.10 of the 2009 MUTCD says, “An interpretation includes a consideration of the application and operation of standard traffic control devices, official meanings of standard traffic control devices, or the variations from standard device designs.” Your document does not present questions regarding the application or operation of any standard traffic control device, the official meaning of a standard traffic control device, or a variation from a standard traffic control device design. Therefore, we are unable to offer an official interpretation in response to your document.

In your document that requests an official interpretation, you ask two questions. This e-mail response provides our answers to your two questions. Your questions and our responses are as follows:

1) Is “texturing” (decorative-patterned slight surface depressions) of the road surface permitted in a Bicycle Lane?

The MUTCD does not have any provisions regarding the paving materials that are used for roadways, including in bike lanes, because this is a roadway design decision, not a traffic control device decision. The MUTCD does not even address the pavement marking materials that are used to designate bike lanes except for the recommendation in the second sentence of Paragraph 3 in Section 9C.02 that says, “Consideration should be given to selecting pavement marking materials that will minimize loss of traction for bicycles under wet conditions.” Other publications, such as AASHTO’s “Guide for the Development of Bicycle Facilities”, address the types of paving materials that are suitable for use in a bike lanes. If the brick or stamped asphalt area of the pavement shown in your photograph from Tempe, Arizona is not a suitable riding surface for bicyclists, the selection of this paving material effectively narrows the usable width of the bike lane. The MUTCD does not have any provisions regarding the required or recommended width of a bike lane. Again, this is a roadway design decision and other publications, such as AASHTO’s “Guide for the Development of Bicycle Facilities”, should be consulted regarding the minimum widths of bike lanes.

2) Are other colors (besides the white markings, and optional green colored pavement) permitted within a Bicycle Lane?

The only color of pavement that is permitted to be used as a traffic control device in a bike lane is green. The use of green colored pavement as a traffic control device in a bike lane has been granted interim approval and the memorandum for IA-14 ( describes the conditions under which it may be used by agencies that have obtained the FHWA’s permission to use IA-14 for this purpose. The City of Tempe, Arizona, is one of the agencies that received our permission to use green colored pavement in bike lanes. If the red color shown in your photograph from Tempe, Arizona, is non-retroreflective, is being used as a purely aesthetic treatment, and is not intended to communicate a regulatory, warning, or guidance message to road users, then it is acceptable for use per Paragraph 2 of Section 3G.01. However, if the red color is retroreflective or if it is intended to communicate a regulatory, warning, or guidance message to road users, then it is a traffic control device and the use of the red color would not be compliant with the MUTCD or with the IA-14 memorandum. You would need to check with the City of Tempe to see if they intended this red brick or stamped asphalt area to be a purely aesthetic treatment or a traffic control device.

I hope that this information is helpful to you.

Thanks, Bruce E. Friedman, P.E.

Transportation Specialist, MUTCD Team

Related: also see the Hardy Drive Streetscape Project which was completed around the same time.

See more pics in the gallery

Update Jan 2018

In late 2017, the vast majority of the project was resurfaced with what appears to be a thin top coat of asphalt. This had the, intended or incidental, effect of filling in the texturing in the BL. I have no idea why, since the project entirely rebuilt the road less than three years ago — a full-blown mill and fill. Perhaps this is normal preservation? No idea. In any event there is still a tiny section, about 500′, of textured BL, between Farmer and Ash.

Here’s a good street view which as a lot of history, you can see before the 2015 project, the 2015-2018 with texturing, and the current rendition where the texturing/coloring is now gone.

4 thoughts on “University Drive textured Bike Lane”

  1. (update for 2017: now have to put an extra percent sign, LIKE “%University%”, because beginning this year, there is sometimes some junk in front of the OnRoad and/or CrossingFeature; added that below to the query. There were six crashes in the subject area this year).
    here’s a query to select bicyclist-MV crashes — according to traffic records, there were 21 reported incidents (one of the incidents involved two bicyclists) for the five years from 2009-2013. Remarkably, police found a bicyclist to be Most at Fault (MaF) ALL 21 incidents… this might indicate other problems; and ought to be looked at more closely.
    The injuries were generally low severity, with just 3 being incapacitating.
    There was one no_injury hit and run where the bicyclist ran.

    SELECT i.IncidentID, i.IncidentDateTime IncDateTime, i.IncidentYear IncYr, City, Oncic, i.OfficerId, i.eCollisionManner, i.eLightCondition, i.TotalUnits TotUnits, i.TotalNonMotorists TotNM, i.eInjurySeverity, i.HitAndRunFlag HandR, i.OnRoad, i.CrossingFeature, i.Latitude, i.Longitude, i.eTrafficWayType, i.eIntersectionType, i.eJunctionRelation, i.eWeather, p_bike.UnitNumber b_UnitNumber, p_bike.eNonMotoristLocation, p_bike.eSex b_Sex, p_bike.Age b_Age, p_bike.eViolation1 b_Violation1, p_bike.eSafetyDevice b_SafetyDevice, p_bike.ePersonType b_PersonType, u_bike.eLane b_Lane, u_bike.eTravelDirection b_Direction, u_bike.eUnitAction b_Action, p_car.UnitNumber c_UnitNumber, p_car.eSex c_Sex, p_car.Age c_Age, p_car.eViolation1 c_Violation1, u_car.eLane c_Lane, u_car.eTravelDirection c_Direction, u_car.eUnitAction c_Action FROM (((( 2017_incident AS i JOIN 2017_person AS p_bike ON i.IncidentID = p_bike.IncidentID) JOIN 2017_unit AS u_bike ON p_bike.UnitID = u_bike.UnitID) JOIN 2017_person AS p_car ON i.IncidentID = p_car.IncidentID) JOIN 2017_unit AS u_car ON p_car.UnitID = u_car.UnitID ) LEFT OUTER JOIN LOVCounty ON i.CountyId = LEFT OUTER JOIN LOVCity ON i.CityId = LEFT OUTER JOIN LOVNcic AS OffNcic ON i.OfficerNcic = LEFT OUTER JOIN LOVNcic AS ExtNcic ON i.ExtendedNcic = WHERE p_bike.ePersonType = 'PEDALCYCLIST' AND p_car.ePersonType='DRIVER' AND 
    (Longitude < -111.943559 AND Longitude > -111.959684) AND 
    (Latitude > 33.4218 AND Latitude < 33.4221 ) AND
    (OnRoad LIKE "%University%" OR CrossingFeature LIKE "%University%") 
    ORDER BY i.IncidentID;
  2. Who produces these designs?
    According to a presentation on the city project page
    (which is much appreciated by the way)
    Besides the City of Tempe, the outside consultants were from Kimberly Horn Assoc.
    A number of these folks are “PE, PTOE” (Professional Traffic Operations Engineer); i.e. licensed professional traffic engineers. E.g Julian Dresang, City of Tempe; Ray Yparraguirre of KHA.
    Was there a request for experimentation for the red stripe? for the texture? If not, why not?

  3. Found in Verde Valley Master Transportation Studies materials, specifically the public involvement / presentation document.

    Recommended Multi-modal Improvements
    Bicyclist Safety Improvement Strategies
    Texture Pavement (in a bike lane. The photo in the presentation is a shot of the University Drive / Tempe project in the article, above)
    – Transmits sound and vibration to drivers
    – Defined space for pedalcyclists
    – Encourages motorists to yield
    – Requires additional on-going maintenance
    – Bike lanes may need to be widened

    This email was sent to the contacts listed for the plan:

    To Date Dec 3 1:33pm

    I am not in favor of textured surfaces in Bike lanes.
    In any event, any bike lanes constructed should have a minimum of 4 feet of usable operating space, exclusive of any gutter pans, grates, etc.
    If you insist on texturing, the usable width is also exclusive of textured area.

    Ed Beighe

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