Thru Traffic

[Alex]

Taken from Best and worst Control City:

Basically, this is another spinoff of the Control Cities thread.

So whats your favorite or best listed Control City and the worst or your least favorite one and why?

I'll start with

Favorite  'Other Desert Cities' (I know i might get some disagreements on this) to me though it is a bit unique, and I think it makes sense given the Coachella Valley Destinations.  Plus I don't see a reason for Phoenix to be listed before Indio.  I mean Las Vegas isn't listed on the 15 until Barstow.

Least Favorite 605 in Los Angeles area, 'Thru Traffic' I really think that there should be a control city on the 605. 

Instances of "Thru Traffic" as the control point really grind my gears, heh. Anyway, in the effort of uselessness, control cities of Thru Traffic:



Virginia 195 Toll (Downtown Expressway)



Interstate 295 - Portland, Maine.



Interstate 95 - Bangor, Maine.



One of many instances on the New Jersey Turnpike.



Aforementioned Interstate 605.

[Interstate Trav]

I wonder why the US named so many cities 'Thru Traffic'.   I wonder what 'Thru Traffic' California is like, or 'Thru Traffic' New Jersey.  Seems to be a popular name.

[J N Winkler]

"THRU TRAFFIC" was recommended for pull-through signs in the initial edition of the AASHO Interstate signing manual--this is part of the reason there are so many instances of "THRU TRAFFIC" still persisting.  The present control-cities policy and the decision map that goes with it postdate Interstate signing itself, though I am not sure by how much.

Another early signing practice, which received heavy criticism during Congressional hearings into freeway guide signing in the late 1960's and was abandoned with the advent of "positive guidance" in the 1970's, was to use a downward-pointing arrow with an exit destination over a through lane.  The rationale for this practice was to tell traffic wishing to take that exit that it needed to be in that lane in order to access the exit ramp.  What tended to happen in practice, however, is that drivers assumed that the downward-pointing arrow meant the lane was going to be dropped, so they moved unnecessarily into the next lane to the left (often under a "THRU TRAFFIC" pull-through) and wound up obstructing faster traffic wishing to pass.

[hobsini2]

My biggest objections to the "Thru Traffic" sign is when there is no shield marker so you know what highway is straight.  It also looks better.

[architect77]

I like the use of "THRU TRAFFIC" when the highway is forking and those unfamiliar to the area must make lane choices.

What towns would be appropriate control cities for the NJ Turnpike or the 605? Secaucus? Does the 605 terminate in any relevant destination?

When I lived in Los Angeles I thought the 605 (sans control city) was a testament of how huge LA was.... a mega-freeway merely connecting other mega-freeways in sort of the middle of a megalopolis.

[RoadWarrior56]

A 2nd to the thread above.  In my childhood day (1st generation interstation construction), I saw "Thru Traffic" overhead signs all over the place.  I think control cities on "pull-through" signs came late 60's or early 70's.

[Brian556]

I remember there being at least one of these on I-30 in Fort Worth, Tx

[Alps]

NJ Turnpike ought to have the following control cities (note that the MUTCD may disagree):
Del Mem Bridge (SB only), Camden (via exit 3 NB or 4 SB), New Brunswick (via exit 9), Newark (via exit 13A or 14), Geo Wash Bridge (NB only) - Due to the number of exits for NY, I wouldn't sign the through route as NY. Exits 10, 13, 14, 15E, 16E, or 18 all lead there.

[Landshark]

I-5 SB in Olympia needs the THRU TRAFFIC signage over the two far left lanes to keep people out of the lane that merges into US-101.   If more drivers going beyond US-101 on I-5 stayed to the left, there would less congestion.  Better yet, they better design the 104/105 exits and interchange so the signs would be unnecessary.

[Interstate Trav]

I like the use of "THRU TRAFFIC" when the highway is forking and those unfamiliar to the area must make lane choices.

What towns would be appropriate control cities for the NJ Turnpike or the 605? Secaucus? Does the 605 terminate in any relevant destination?

When I lived in Los Angeles I thought the 605 (sans control city) was a testament of how huge LA was.... a mega-freeway merely connecting other mega-freeways in sort of the middle of a megalopolis.

Going South 605 terminates I guess you could say close to Long Beach.  Going North, it's near Duarte and Azusa.  Good point though about 605 being mainly a transition freeway. 

[MDOTFanFB]

There is also one on U.S. 24/Telegraph Road NB in Taylor, MI:



I believe they could've gone for Dearborn Heights instead.

[ctsignguy]

I wonder why the US named so many cities 'Thru Traffic'.   I wonder what 'Thru Traffic' California is like, or 'Thru Traffic' New Jersey.  Seems to be a popular name.

And when i was a misbegotten youth, the Conencticut Turnpike had many signs indicating 'SHORE POINTS NEXT EXIT"....i swore up and down there was a mystical town called Shore Points, and it had to be the LONGEST town ever (85 miles long, but a half-mile wide!)

[Ian]

I think the New Jersey Turnpike thru traffic pull throughs are being phased out however.

[InterstateNG]

I believe they could've gone for Dearborn Heights instead.

MDOT usually uses Pontiac for 24NB, as seen at the junction with I-96.

[Michael]

I wonder why the US named so many cities 'Thru Traffic'.   I wonder what 'Thru Traffic' California is like, or 'Thru Traffic' New Jersey.  Seems to be a popular name.

I actually LOL'd.  I wonder where Thru Traffic, NY is.

[froggie]

I like MnDOT's solution the best:

[Alex]

I like MnDOT's solution the best:

Agreed. This was always a NJ standard too (is it still?):

[J N Winkler]

Agreed. This was always a NJ standard too (is it still?):

It is actually a national standard.  The MUTCD does not require downward-pointing arrows on pull-through signs (which both the Minnesota and NJ signs are) unless unusual road geometry, major interchanges, or multilane exits are involved.

[roadfro]

Agreed. This was always a NJ standard too (is it still?):

It is actually a national standard.  The MUTCD does not require downward-pointing arrows on pull-through signs (which both the Minnesota and NJ signs are) unless unusual road geometry, major interchanges, or multilane exits are involved.

The MUTCD examples would typically show a control city in cases like the one pictured above, not just the shield and direction.  With or without a control city, something like that is more helpful than "Thru Traffic" in these pull-through examples with simple geometry.

[J N Winkler]

The MUTCD examples would typically show a control city in cases like the one pictured above, not just the shield and direction.  With or without a control city, something like that is more helpful than "Thru Traffic" in these pull-through examples with simple geometry.

Yes, the MUTCD examples invariably show a control city, but I don't think there is anything in the MUTCD which says that a control city HAS to be used at any given location--the guidelines that are provided instead call for consistency and continuity (if one pull-through sign has a control city, the next pull-through sign on the same segment of route should have the same control city), as well as conformity with external guidelines where they exist (use of control cities off the AASHTO list on Interstates, for example).  The MUTCD advice with regard to control cities has much in common with the advice public health agencies give about drinking alcohol:  if you must do it, do it responsibly.

There are some large differences between states in whether and how control cities are used on beltways.  The approach taken by KDOT is not to use them, and I prefer this on engineering grounds.  However, this has the perverse result that Wichita is much better signed on the Missouri side of the Kansas City metropolitan area (where MoDOT uses control cities on beltways, so that "Wichita" appears frequently on I-435 signs) and, indeed, in Oklahoma City (where Wichita is the control city for northbound I-35) than it is anywhere in Kansas (the southbound destination at the I-135/I-70 interchange, for example, is "Salina" since the interchange is north of Salina proper).  This combination of approaches makes Wichita out to be Kansas' embarrassing secret.

[njroadhorse]

There are some large differences between states in whether and how control cities are used on beltways.  The approach taken by KDOT is not to use them, and I prefer this on engineering grounds. 

Personally, I feel that on beltways, that there should be two control cities mentioned: one local destination and then another destination that is not on the beltway, but instead on the next major highway that the beltway intersects.

Example: I-270 North/Inner in Ohio at MM 15.  The local control city here could be Dublin, and the non-beltway control city would be Cleveland or Mansfield, since I-270's next major interstate junction is I-71, and it would make the most sense for either of those towns to be included.

[architect77]

I think beltways should be identified as beltways on signage. Deciding which control city to use can become somewhat arbitrary. Here are two junctions which Charlotte's "Outerbelt" on I-85 North. I wouldn't have chosen either as a control city, but rather Columbia, SC probably.

[Interstate Trav]

There are some large differences between states in whether and how control cities are used on beltways.  The approach taken by KDOT is not to use them, and I prefer this on engineering grounds. 

Personally, I feel that on beltways, that there should be two control cities mentioned: one local destination and then another destination that is not on the beltway, but instead on the next major highway that the beltway intersects.

Example: I-270 North/Inner in Ohio at MM 15.  The local control city here could be Dublin, and the non-beltway control city would be Cleveland or Mansfield, since I-270's next major interstate junction is I-71, and it would make the most sense for either of those towns to be included.

On spurs as well, for example in California on I-210 westbound San Fernando and Sacramento, and on I-210 Eastbound Redlands and Palm Springs.

[TheStranger]

On spurs as well, for example in California on I-210 westbound San Fernando and Sacramento, and on I-210 Eastbound Redlands and Palm Springs.

IIRC, Sacramento is presently only I-210's westbound control city starting in Sunland or so.

San Bernardino is the primary eastbound control city after Pasadena if I'm not mistaken.

[FreewayDan]

San Bernardino is the primary eastbound control city after Pasadena if I'm not mistaken.

It sure is.  Even before the 210 was extended out to San Bernardino begining in 2001.