- Cyclists will have to merge into traffic from the bike lanes at each and every roundabout they encounter, since the bike lanes must terminate in each roundabout to be a safe configuration. Alternatively, cyclists can exit the bike lane and get on short sidewalks/multiuse paths circumnavigating the roundabout to get around with pedestrians as pedestrians (as we can at the San I roundabout and as shown in the pic below). The sidepath option can be slower and cumbersome if you are continuing straight ahead or making a "left turn', i.e., travelling 180 or 270 degrees through the roundabout before exiting. Bike lanes in roundabouts create serious conflicts, i.e., a 360 degree "coffin corner". That's why they are stopped at modern roundabouts and why we don't have them within the San Ildefonso roundabout.
Grand Junction, CO roundabout. Note abrupt termination of bike lanes |
- Roundabouts are touted as being safer to motorists because they replace high speed crashes with low speed crashes and they eliminate high speed "red light running" crashes entirely. This indirectly benefits cyclists and pedestrians if you do get into a crash with a car. Having said that, being hit at 15 mph while in a car means a bent fender. Being hit at 15 mph on your bike or while on foot should not be trivialized.
- The bike lane terminations shown at last night's meeting were very abrupt, with solid bike lane stripes continuing right up to the end of the bike lane segment as it abruptly terminates at the roundabout. That common design explicitly discourages merging in advance, i.e., encourages cyclists to dart into the travel lane at the last minute at the stripe termination, rather than encouraging a smooth and timely vehicular merge. Sudden, graceless lane changes are much to the consternation of the motorist slamming on his brakes to avoid hitting you while calling on God's fallen angels to deal with your presence on earth. A better design would provide a more substantial merge zone with broken stripes or a yet to be determined MUTCD standard colored lane zone indicating cyclists are merging into the travel lane with other traffic. Remember: as the person changing lanes, you DO NOT have the right of way when changing lanes unless state law and special lane markings apply: the person who already occupies the lane has the right of way. You must negotiate into the travel lane.
- That said, it will be difficult to negotiate your way into a travel lane at peak traffic loads if traffic is backed up from the roundabout. It remains to be seen how the traffic modellers think traffic will be backed up out of these proposed roundabouts during heavy periods, but chances are traffic will indeed be heavy and you will be negotiating into the travel lane in close quarters. Is that bike friendly?
- The design shown by the consultants, with 11 foot vehicle lanes and 8 foot bike lanes, doesn't actually terminate the bike lane in the roundabout with a physical barrier as in the picture above. Instead, the space formerly occupied by the bike lane continues without the physical obstruction shown above, but instead with crosshatched pavement, i.e., an indication you should not be riding there but in the travel lane. That is done to provide emergency driving space for motorists if the motor vehicle lane is blocked (by a crash, etc.). It should also make plowing easier. But I strongly suspect, as Neale Pickett did, that at least some cyclists will in fact continue to ride in that crosshatched zone and get squeezed into a "coffin corner" in the roundabout.
- If we continue to have numerous curb-cuts, i.e., left and right turns, then Trinity Drive bike lanes will put cyclists to the right of right turning motorists ("right hook crash") and potentially screened from left turning motorists ("left cross crash") if final design includes left turn bays between roundabouts. This may be especially problematic if the cyclist is not alert, engaged, and can bike-handle to avoid trouble (i.e., perform a panic stop or instant turn).
- Bike lanes will end near the East end of town by the airport. Ironically, this is one location where they may do the most good since there are few turning and crossing points once you clear town. We were told that a Class I bike-ped path would continue on the North side of the highway out to the county line. However, the exact details could make this a blessing or a curse: Short sight lines were designed into the Canyon Rim Trail which although scenic, make the design speed less, in my estimation, than 10 mph--cyclists riding much faster than that ride up on unsuspecting walkers or oncoming cyclists much too quickly. This pretty but patently unsafe design presumably would not be done again on a path designed for transportation.
- No one identified how Eastbound cyclists will cross the road to get back and forth onto the north-side path (I assume most cyclists will not want to use the Canyon Rim Trail and cross the 50 mph road out by Entrada park).
- Finally, as Neale Pickett noted, if trees are planted between the multiuse path and the road, the path will be shaded in winter, leading to snow and ice buildup.
Neale Pickett asked if the consulting company had considered Bicycling Level of Service (described here by Sprinkle Consulting, Inc. They had not. For those not familiar, a Bicycling Level of Service (BLOS) model (originally published in the Transportation Research Record) is not about how long it takes for you to get through an intersection, which is how it is defined for traditional motor traffic. BLOS is a measurable number that reflects bicycle-friendliness, according to the authors. It takes into account average traffic loads, speed limits, lane widths, heavy vehicle (i.e., truck) useage, and surface quality in an equation spitting out a number, which obviously makes it objective. I say that somewhat sarcastically because the question isn't simply "how long will I be sitting in this freakin' intersection?", but instead attempts to answer the fuzzier question of what the authors thought bicyclists wanted. They may well be right. Well, go read the article. The Sprinkle, 2006 version of the TRR paper is online.
Seriously, none of the various options proposed for Trinity is going to make the road the kind of place you plop an inexperienced, timid cyclist and expect him or her to ride along in mindless bliss, i.e., the "B or C cyclist" that is the asserted target of these "bike friendly" designs. This is a heavily used arterial which, during rush hours, is best suited for competent cyclists, regardless of whether we build the A, B, or C options. Or, for that matter, if we do nothing at all. I think that if we want a bikeway suitable for the inexperienced or less confident rider, a separate and well-designed right of way, as suggested by former Councilor Robert Gibson, should be considered. Trinity cannot be all things to all people. At best, it will be a soundly engineered compromise.
If you really want to feel like a road is "friendly", I suggest you first contact an LCI such as Neale or Amy Pickett or myself and take a Traffic Skills 101 course. Like most activities, one is more confident and relaxed when one is trained to do the task at hand. Bike lanes or roundabouts are not magic bullets. The closest we come to a magic bullet is the skilled cyclist riding well. In that context, the present design of Trinity integrates cyclists into traffic where they are more visible and where bicyclist actions are constrained to be vehicular, and thus should be more easily understood by other users of the roadway. Perhaps Trinity Drive is a bicyclist friendly arterial just as it is. My concern is that by adding bicycle-specific facilities without a clear evaluation of their safety aspects in that specific corridor design, we could be getting all show and no substance or at worst, adding hazards.
The question of what to do with Trinity has less to do with cycling than it has to do with making the road compatible with the County's continued push to build up an urban environment on the South side of the street, which will continue with Trinity Site development and future development after the proposed DP Road land transfer from DOE to the County. In other words, making Trinity Drive more of a "complete street" that exhibits synergy with rather than providing an obstacle between surrounding land uses. If I were moving into town and had kids, I sure as hell wouldn't want to plop them down in a new development separated from the rest of the built environment by a high speed road looking like the Cerrillos corridor in Santa Fe. Neither would I want to be pushing a big cart of groceries across five lanes of Trinity from a newly relocated Smiths (I suppose we could put in ped overpasses or tunnels except these cost millions and are typically cut out of a project. Guess who loses?)
That's the rub--people live here. To say that reducing lanes on Trinity is equivalent to reducing NM 502 (in the valley) or US 84/285 to two lanes, as Victor Gavron suggested last night, ignores that those are long distance rural highways. Trinity is a very short road in an urban setting. That's not apples vs. oranges, its apples vs. orangutans. We have willingly built up both north and south sides of Trinity with residential and commercial properties and plan on building more. One may not want to divide those north and south of Trinity with a very wide and fast arterial (albeit people buying land south of Trinity obviously knew what they bought into). Compromises to surrounding land use may have to be considered in light of decisions we have already made in our land use planning. That is the dilemma we have already forced on ourselves. The bottom line is this: Trinity MUST function acceptably (i.e. acceptable LOS) as an arterial, but it need not be a fast arterial.
Trinity Drive Corridor Study page (County)
Stay tuned.
1 comment:
They pointed out that less courageous riders can take advantage of the transition from bike lane to off-road multi-purpose trail at the roundabouts.
Post a Comment