By Annie Weinstock
Lately, the internet is abuzz about the 2nd Avenue bike lane. Clarence Eckerson took some peak-hour counts of bicycles and vehicles and found that the volumes aren’t vastly different from each other, despite the vastly disproportionate amount of space allotted to mixed traffic.
Eckerson’s question regarding whether we need a wider protected bike lane was picked up by city council members and mayoral hopefuls and now calls to do it are growing.
With increasing bike volumes, wider bike lanes seem like a no-brainer. As Chris Bruntlett, of the organization Dutch Cycling Embassy told me:
Additional width creates inclusive and comfortable space for side-by-side cycling, safe passing, and mixing of users of slightly different speeds, masses, and abilities (children, elderly, e-bikes, cargo bikes, and even manual and electric wheelchairs).
So I dug into the numbers to assess the technical case for bike lane widening on 2nd Avenue, around NYC, and beyond.
US bike lane guidelines largely assume low bike flows
The bike lane width guidelines in the US are almost entirely based on cyclist safety vis-à-vis other vehicles. Very little guidance is provided for bike lane widths that adjust with increasing bicycle volumes. NACTO, who developed the Urban Bikeway Design Guide, understood that bicycle volumes in the US have historically been extremely low, and focused their guidelines on keeping cyclists safe from moving traffic. Indeed, the NYC Street Design Manual, 3rd Edition includes many of the same guidelines.
NACTO’s guide does make one important mention of designing bicycle facilities around bicycle volumes in their recommendations around two-way cycle tracks — this was not included in the NYC Street Design Manual. These recommendations come from the famed Design Manual for Bicycle Traffic by the Dutch group CROW.
What is needed, now that bike volumes in parts of NYC [are] may be outgrowing the current infrastructure, are standards which guide bike lane width based on bicycle volumes on a corridor. This will allow advocates and citizens to better hold the city accountable for their design choices.
Use the Dutch standards
While a few American cities are only just starting to find themselves in the uncharted territory of having an overflow of cyclists, this problem is hardly novel for the Dutch. The Design Manual for Bicycle Traffic guides the Dutch government in its cycle lane design, and it is also influential in many cities worldwide.
Here are the CROW standards for bike lane widths, based on rush hour bicycle volumes.
New York City, and other US cities with growing bike volumes, should adopt this guidance immediately and should retrofit existing bike lanes that are not up to standard.
Certainly, it would be a bold move politically to adopt the very forward-thinking Dutch standards. Today, bike lanes in most US cities are largely designed to minimize inconvenience to drivers, rather than by using any standard metrics that would provide cyclists a safe and comfortable ride. If US cities actually care about Vision Zero and about shifting more people out of their cars, they should design around these standards.
What these standards would mean for New York City
The NYCDOT bicycle volume data is surprisingly thin (2019 daily volumes at several locations is the most recent available), but I did an analysis on several corridors with what is out there.
1st, 2nd, 8th, and 9th Avenues
1st Avenue, 2nd Avenue, 8th Avenue, and 9th Avenue all saw similar daily volumes in 2019 (between 2,500-3,300 daily). I used a peak hour factor of .15 to put this in peak hourly terms and averaged them out to 375-480 peak hour cyclists on each of these facilities. This is lower than the counts that Clarence Eckerson made on 2nd Avenue last week but, bicycle volumes have been increasing during the pandemic, so 600 peak hour cyclists on 2nd Avenue in 2021 seems reasonable.
Each of the above avenues includes, roughly, a one-way parking-protected bike lane with a width of 6 feet and a 4-foot buffer.
Based on the CROW guidelines above, these one-way bike paths should all be widened to 8–10 feet in general. However, given the steady growth in cycling in NYC, NYCDOT should expect demand on most, if not all, of these facilities to grow past 750 peak hour cyclists in the coming years (1st and 2nd Avenues will most likely do this before 8th and 9th). This likelihood, combined with the growing numbers of wider cargo bikes coming online, and the incredible speed differentials between bicyclists in NYC, would make it reasonable to widen each of these bike lanes to somewhere between 11.5–13 feet. Some of this width could come out of the existing four-foot buffer between the bike path and parked cars, but some width is still needed for an independent buffer.
Importantly, the 1st and 2nd Avenue bike paths are the only pieces of safe bicycle infrastructure on the east side. Therefore, widening those bike paths is not the only measure NYCDOT should be taking to manage the volumes on those paths. They should also be filling the gaps in the network. This would simultaneously help to grow the bicycling mode share in NYC and somewhat reduce bike volumes on 1st & 2nd Avenues.
Third Avenue would be a very reasonable option, as would Park Avenue (even better — both).
On Park, we might also include a BRT adjacent to this bike lane to help manage some of the high bus demand on the east side.
East River Bridges
While the bicycle volumes on the East River Bridges all outpace the widths given on those bridges, both the Brooklyn and Queensboro Bridges are preparing to reallocate a mixed traffic lane for cyclists. This is highly commendable… if it actually happens.
However, the plan on the Brooklyn Bridge is to convert one ten-foot car lane into what amounts to an eight-foot bidirectional bike path. This is woefully narrow based on the guidelines above, given that the Brooklyn Bridge already sees up to 375 peak hourly bicycles (better data would confirm this number). Additionally, it is likely that bike volumes on the Brooklyn Bridge today are suppressed by the limited space and conflicts with pedestrians. With dedicated space, those volumes are likely to increase.
It is also worth noting that on bridges, some extra width is needed due to the speeds of bicycles associated with the downward slope. It is, therefore, strongly recommended, that the city listen to the Bridges 4 People activists who are calling for an additional mixed traffic lane dedicated to bicycles on the Brooklyn Bridge in order to meet the needs of the bike volumes there now and into the future.
The Williamsburg Bridge bike path is the highest volume bike path in the city, topping off at 9,500 daily cyclists in September 2020. With an 11-foot bidirectional bike lane, almost four feet short of the CROW standard, this path should also be reviewed.
Finally, as I’ve discussed before, the bike volumes on the Manhattan Bridge outpace the width of the Manhattan Bridge bike path. The maximum width on the Manhattan Bridge bike path is 9.9 feet. The maximum peak hourly bike volumes on the Manhattan Bridge, based on a daily maximum of 8,800 in September 2020, is around 900. This surely justifies the 14.8 feet listed in the CROW guidelines — ideally, coming from a lane on the lower level.
NYCDOT should review and plan all of its bike facilities according to these standards
As I mentioned above, NYCDOT posts very little detailed data on bicycle volumes. What they post is aggregated daily bicycle volumes on some facilities. None of it is broken down by hour or by segment. My vague understanding is that they do collect more fine-grained data but that they don’t really use it for much.
If they do actually collect this data, they should use it! If they don’t collect this data, they should!
They should then analyze it, like what I’ve done above, to determine what widths their existing bike paths should actually be in order to provide sufficient space for the growing NYC cycling population. Some facilities that I did not look at above, but which probably require a more careful look, include the Hudson River Greenway, the Brooklyn Waterfront Greenway, the Prospect Park West bike path, the East River Greenway, and others.
When planning a new bike path, cities should be proactive, rather than reactive. Today, NYCDOT generally chooses bike lane widths based on what they believe they can get away with politically. This is most certainly the case with the proposed Parkside Avenue bidirectional bike path, which is planned to be a very narrow six feet in total. NYCDOT should instead project the number of expected cyclists and plan the widths around the well-established, best practice guidelines.