For a while, I've sort of assumed that Connecticut favors undivided 4-lane roads over divided highways for easier plowing (and similar for most interchanges with surface streets providing only the minimum number of ramps).
But is this valid at all? How do some states take climate into account when designing road layout? Examples could be channelization, interchange types, roadway features, etc.
(Road materials would be a more obvious connection; Florida pavement probably differs from Michigan pavement.)
I-95 in northern Maine had jughandles for snowplows to turn around at when it was two-lane. (Railroads in snowy areas did the same with loop tracks rather than wyes.)
The main thing is choice of maximum superelevation, with higher values of maximum superelevation being used in areas judged less susceptible to icing.
You may already know this, but the winters here in MI are very brutal! Most of I-275 was built during the 1970's using what was called "the new concrete" Continuous Reinforced Concrete. But after a few winters cracks began to develop, they would become so big they would (and have) take a toll on the numerous cars that traveled on it!!! As a result, in the 90's, MDOT decided to rebuild the entire length of I-275 from Frenchtown Township to Farmington Hills from scratch, the last six miles were completed in 1999. To compare, before M-8/Davison Freeway was rebuilt, it's concrete has seen constant use ever since it was first poured wwwwwaaaaaaayyyyyyy back in 1944, during WWII! In fact, MDOT no longer uses Continuous Reinforced Concrete.
Quote from: J N Winkler on March 09, 2011, 07:20:45 PM
The main thing is choice of maximum superelevation, with higher values of maximum superelevation being used in areas judged less susceptible to icing.
NY went from 8% to 6% (same as NJ) for mainly this reason.
Another thing I have wondered about: minimum grades in curbed areas. Michigan DOT, for example, requires a minimum longitudinal grade (0.3% absolute minimum, 0.5% desirable minimum) for drainage in areas where roads either have curbs with gutter, or are expected to get them at some point in the future. Usually this applies to surface streets but I have seen scoping reports which call for the minimum grade to be observed on urban freeways where it is proposed to put in curbs in back of the shoulder. The minimum grade is completely separate from any crossfall provided on tangent segments (Michigan DOT likes 2%) or superelevation on curves.
Many jurisdictions use steeper crossfall on the shoulders than on the traveled way. In Kansas, for example, crossfall in the traveled way can vary from about 1.5% to about 2% but shoulders are invariably 4%. This applies regardless of pavement type (indeed, if you put your foot astride a shoulder stripe on a Kansas highway, you can feel the grade break through your shoe). I wonder if this has something to do with snow and ice removal.
In NJ: Minimum grade 0.5%, first lane 1.5%, next lane 2.0% (or for wide highways, two lanes each), shoulders 4%. NJ Turnpike goes I believe up to 8% on shoulders. It's definitely drainage related.
Quote from: kurumi on March 09, 2011, 05:34:59 PM
For a while, I've sort of assumed that Connecticut favors undivided 4-lane roads over divided highways for easier plowing (and similar for most interchanges with surface streets providing only the minimum number of ramps).
(Road materials would be a more obvious connection; Florida pavement probably differs from Michigan pavement.)
Unfortunately, for CT I think it is simply two things: Poor planning and NIMBYism. Look at the new CT-66 in Middlefield.
I think it's more just typical New England thinking small. Same reason you will never see a non-freeway up here posted above 50.
Quote from: Duke87 on March 12, 2011, 08:58:46 AM
I think it's more just typical New England thinking small. Same reason you will never see a non-freeway up here posted above 50.
I've seen 55 on Mass 9. :P And let's not go into the 55's all over Maine.