Originally Posted by
genec
Your method of vehicular cycling only works when the number of cyclists is statistically low. (and must be maintained at a low number)
Expecting motorists to slow down for massive numbers of merging cyclists is an unsustainable system.
I know we have discussed this in the past. But this isn't clear to me. Yes, if you ...
(1) take the same roads,
(2) keep present motoring traffic patterns the same,
(3) increase the population thereby increasing flows, and
(4) increase cycling on these same roads
... you will get a lot of congestion. But people respond to conditions and change their behavior to avoid doomsday scenarios.
Originally Posted by
sggoodri
Unsustainable for whom?
Where I have seen motor traffic mixed with traffic from large group rides, the motor traffic must operate slowly where there are inadequate passing opportunities, but speeds up elsewhere. Increased bike traffic in the US would likely result in more passing opportunities integrated into roadways.
As the number of left-turning cyclists on the road increases, this will potentially require motorists to slow more often, but this can be mitigated by access control (such as raised medians) minimizing the number of left turns on important arterials.
The intersection-merge issue essentially boils down whether motorists require more time to safely merge with bike traffic than to wait for a sufficient gap to safely cross it. I think a larger gap is required for crossing bike traffic than to merge into it. If the gap is created by signals rather than naturally, the signals must delay both motor traffic and cycle traffic at times. It's not clear to me that this is a win for either cyclists or motorists.
I think one can show that slower and better flowing traffic can move more people than "the" present system. Quotes are used since -- this is anecdotally true, but I suspect it is also true by some metrics -- traffic systems vary quite a bit.
Originally Posted by
The Human Car
IMHO a lot depends on where a locality is on the evolutionary development of being bike friendly. My thoughts are the first stress should be in establishing major routes that function like bike arterials, these should be near or connect origins and destinations (areas with a high latent demand score) with the purpose of focusing bike traffic along a corridor. Establishing a network is secondary to accommodations along or parallel to transportation corridors. These corridors should be at least 2-5 miles long along the fastest route for cyclists (traffic lights or few stop signs) that BLOC grade C (or better) can be established. The next phase can extend, connect and feather out these bike arterials via sharrows in BLOC grade D roads or use other treatments on quieter residential roads.
In theory I support connecting nearby neighborhoods with shopping centers but I have seen very little momentum established by such facilities, I suspect that is because the athletic do not find such things that desirable, they want a good run they can do after work or on the weekend. I will also mention that joggers found our first efforts in bike accommodations very desirable so again I will stress the best facilities are those that can function well as both transportation and recreational facilities. And as far as comfort goes on busy streets for recreation, trust the BLOC score and for transportation use trust a high latent demand score and lastly you need length to draw out the athletic.
I see accommodating cyclists a lot like establishing a mini commuter rail system. The first effort is very much concerned about demand, ROW and length of trip to make the effort viable. After a successful "line" is established then discussions of connectivity and expansion are considered but it all starts or centers around lines and corridors IMHO.
As far as splitting or creating alternate routes I am not seeing much evidence on the desirability or viability of such things but so far my experience is those that oppose bike lanes on busy roads are mostly happy with BLOC C accommodations after experiencing them for awhile.
I agree strongly with the emphasized section. In my experience, one can often look at a map and quickly identify "cycling unfriendly" bottlenecks that prevent a broad grid accessible to the general population. If you open the spigot at these bottlenecks I think that more people will seriously consider an alternative method of travel under certain conditions such as an increase in fuel costs. Obviously some transportation grids/systems have more bottlenecks than others.