copyright 1998, Ben Gomberg
We have an interesting challenge in Chicago. Sidewalk widening/improvements under Mayor Daley's "Neighborhoods Alive" program vs. establishing bike lanes, a key component of Mayor Daley's Bike 2000 Plan. Bottom line: The road where we want to establish bike lanes will be 44' wide curb to curb after the sidewalks are widened. Question: Are bike lanes on both sides possible, given that we must provide parking and a travel lane on each side? If so, what cross-section do you recommend and where have they worked? Closing facts: There are no alternate streets to use, parking is continuous, and traffic moves at 30 M.P.H.
Here's what the bicycle coordinators of nine cities had to say...
44'. is our minimum width for keeping parking and installing bike lanes. We're doing it everywhere we can and need to and have had no problems yet.
Whenever streets are being reconstructed, we try to make improvements for bicycling and walking. If there is "extra" room in the roadway, such as extra wide travel lanes, we stripe bike lanes or guide lines. Our preferred dimensions are 11' motor vehicle lanes, 5-6' bike lanes (minimum 5' against parking, 4' against curb (we have granite curbs, no gutter pans) and 8' parking lanes (minimum 7').
Guide lines, also known as "edge" lines, are provided where there is insufficient room for a bike lane, for example, where removing parking to establish bike lanes is unacceptable to the community. The guide lines channel motor vehicle traffic away from parked cars and provide some breathing room for the cyclists. A roadway with guide lines might have 11' travel lanes and what look like 10' parking lanes.
The feedback received from the bicycle community is that guide lines, while not a substitute for bike lanes, offer significant advantages over wide travel lanes, including discouraging speeding and making driver positioning more predictable.
We have also made significant changes on two major streets with four travel lanes, bringing them down to three, adding bike lanes and, in one case, also widening the sidewalk. (For more information, refer to the "Striping Bike Lanes: Overcoming Implementation Challenges in Urban Areas" article in the ProBike ProWalk '96 conference proceedings.)
The contortions we have to go through to retain parking! But, we wouldn't get where we are without accommodating it.
If the street is being reconfigured to widen the sidewalks, does that leave room in the right-of-way to add parking bays for parking on one side or did the sidewalks narrow the curb to curb width? Parking bays might get to be too expensive, plus you do lose some of the parking. If there is any way to reduce the parking to one side of the street, that would be great, but I gathered that had already been considered.
Assuming you must provide travel lanes, parking, and bike lanes in each direction, then the parking turnover rate and parking volume will critically affect how well the bike lanes will work. Here are two examples:
We have a collector street with 6,000 -8,000 average daily traffic volume, where there are also buses and bike lanes. It's 36' wide but only has parking on one side, so the lane widths would be similar to what you are stuck with (7' parking, 5' bike lanes, 10' travel lanes--we actually did 9 _' travel lanes). Speed is 30 m.p.h.. It works because it's in a residential setting; parking is sporadic and turnover is low, plus the traffic volume is relatively light, even with the buses (which are 8 _' wide).
However, we have a 5' bike lane downtown between a 7' parking lane and a 10' travel lane (it has 2 other 10' lanes and is 1-way, so no other bike lane). Average traffic volume is 14,000 vehicles per day, the speed is 20 m.p.h. This is a very uncomfortable bicycle lane to ride in because parking turnover is constant, parking spaces are generally full, and car traffic is constant. When I ride home at rush hour, I'm right on the 8" white line and peering into the windows of each parked car (or I merge into the car lane). It works okay there because the moving cars can crowd away from me and they aren't moving very fast. It couldn't work that way on a 2-way street with opposing traffic in the next lane, unless the opposing traffic was light. I'm assuming that there are aren't many streets with light traffic in Chicago. The saving grace for Eugene is that this bike lane is only 1 block long.
I hope your situation is more like our first example. It would work pretty well. However, if you are looking at high parking turnover rate and volume plus heavy traffic in the travel lanes, I think it could be problematic.
I feel compelled to mention the big reason I support bike lane installation is because if we do not put in a bike lane here, the lane width gets eaten up for some other use such as parking, angled parking, another travel lane, turn pockets, etc. Bike lanes work as "place holders" to dedicate a piece of the road to bicyclists.
A few other details would be helpful before making suggestions: thevolume of traffic on this street; is this street a bus or truck route; what is the adjacent development (residential, neighborhood business, etc.); what is the current/projected bicycle traffic; is parking long term (residential) or high turnover (business related). None-the-less, we have some situations in Madison that are reasonably similar that I will share.
We have several arterial streets in older neighborhoods (both residential and business development) that have a unique configuration. They are essentially 2-lane streets with parking on both sides. However, during peak hours (7:00 - 8:30 am and 4:00 - 5:30 pm) parking is restricted on one side only so the street is three lanes with two lanes in the peak direction (inbound in the am, outbound in the pm). Due to the use of the curb/parking lane as a peak hour travel lane, the curb lane is typically 12-13' wide instead of 7-8'. During off peak hours (21 hours of the day, Madison still has merely a rush "hour") this curb lane meets AASHTO as a combined parking and bike lane. (Note: I am not advocating removable bike lanes. We do not sign these as bike lanes. I am merely pointing out that the configuration is similar to having bike lanes.)
Some of the streets with this configuration are narrow, down to 40' curb face to curb face. What we have done to accomplish this is to narrow the inside lanes as narrow as 9'. Note that these narrow inside lanes are the only travel lanes for all motor vehicles during the 21 hour off peak time, and most of these streets are both bus routes and truck routes.
In your situation, with 44 feet, you would have a 12' combined parking and bike lane and 10' travel lane. You might consider this an improvement for pedestrians (widened sidewalks), an improvement for cyclists (addition of bike lanes) and traffic calming (narrowing of traffic lanes).
You are left with a typical Philadelphia bike lane street. 44' wide streets in Philly are being stripped with 7' parking lanes, 5' bike lanes, and 10' travel lanes. We have used this on several streets and have found that the 7' parking lane adjacent to a 5' bike lane works well because the bike lane shifts the moving cars 5' away from the parked ones. Even if a parked vehicle encroaches in the bike lane a bike can still get by. The 10' travel lane has appeared to calm traffic somewhat. Also, the pedestrian that is crossing the street has only 20' of moving traffic to contend with.
I would suggest that you have the ideal solution provided you don't go under 44'.
With 44', this is what we do on each side of the street: 10' for the travel lane; 7.5' for parking; and 4.5' for a bike lane.
We have done this on numerous streets with 25-35 mph; it works pretty well. On curvy streets it may be a good idea to put the parking at 7' and give an extra 0.5' to each travel lane. On streets with low parking usage, take the parking down to 7' and give the extra 0.5' to each bike lane.
We do not think of this design as "sub-standard" in any way. Our standards allow for 10' wide travel lanes, 7' for parking, and 4.5' wide bike lanes.
To conclude, we feel that the addition of bike lanes on a 44' streets is a vast improvement from the cycling perspective. We have had few problems with this configuration. We have also found that the bike lanes have a traffic calming effect on the order of 2 to 5 mph.
That's going to VERY TIGHT! We usually provide 7'-8' for parking and a MINIMUM 5' wide bike lane next to parked cars. That only leaves a 10' travel lane for motor vehicles, using 7' for parking. How about 8' for parking and a 14' wide curb lane instead?
Our bike lane/parking width standards are listed below. (Note: These numbers are converted from metric measurement, which explains the uncharacteristic numbers.)
On 46' wide streets (one of our typical street widths) we would redistribute space like this:
- 6.6' parking / 5.9' bike lane / 10.5' traffic lane / and the same on other side. Parking is dropped at signalized intersections so that a left turn lane can be established.
This seems to work with minimal impact on capacity for streets with up to approximately 18,000 average daily traffic volume.
On narrower roads (40' wide) we provide parking on only one side, like this:
- 6.6' parking / 5.9' bike lane / 11.1' traffic lane / 11.1 ft. traffic lane / 5.2' bike lane
We have one street (Davenport Road) with substandard widths as a result of a political compromise in order to maintain parking on both sides. In this case we have:
5.9' parking / 5.4' bike lane / 10' traffic lanes (four traffic lanes at this width with frequent bus service and 30,000 average daily traffic) and the same parking/bike lane width on the opposite side. While I hesitate to recommend these widths as general practice, they seem to be working on this street.
We conducted face to face surveys with 84 cyclists on the Davenport Road bike lanes shortly after implementation. Here's their feedback:
- 89% of the cyclists said the bike lanes have made cycling safer on the street; and
- 92% of the cyclists said the bike lane is about the right width. (They could respond: too wide, too narrow, about right, don't know.)
I conducted many of the interviews myself because I was quite concerned with the narrow widths. After the survey I talked to several cyclists further about the width and the message I received was "Sure, the bike lanes could be wider but this is much better than it was."
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