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MoDOT installing J-Turns at rural intersections with no provision for safe bike/ped crossing - disconnecting rural bicycle routes

Submitted by Brent Hugh on Wed, 05/11/2022 - 7:30am

MoDOT has been installing an increasing number of "J-Turns" on rural highways. 

J-Turns convert intersections that are currently perfectly usable by people who bicycle and walk, into intersections that are, in many cases, essentially unusable.

Installing a J-Turn intersection takes a route that was previously an excellent, completely usable bicycle route and disconnects it.

Some J-Turn project examples:


We would appreciate your feedback on the J-Turn design

  • Have you encountered the J-Turn intersection, and what has been your experience with it?  Have you been able to negotiate the intersection successfully or not, by bicycle or on foot?
     
  • Do you have any suggestions for improvements to J-Turn planning or design that could be implemented?
     
  • Have you seen or been involved with design or implementation of J-Turn type intersections that are safely traversable by people who walk or bicycle? Have any advocacy groups, bicycle clubs, etc, been able to successfully work for improvements to this design?

Email director@mobikefed.org with your comments, leave a comment on this page, or comment on MoBikeFed's Facebook page.

Details - What is a J-Turn, and why a J-Turns a problem for people who walk and bicycle?

J-Turns convert the crossing of a minor road with a larger highway from a straight-across type crossing, to one where vehicles wanting to turn left from the major onto the minor road, or go straight across the major road, must go some distance past the intersection, merge into the left lane and then a special J-Turn lane, make  a  U-Turn, and then come back to the intersection:

    

The problem for pedestrians is that there is now no safe path to cross the major intersection.

The problem for bicyclists is that, in order to cross, they must enter the major highway, ride a significant distance, merge left across two lanes of traffic (usually fast-moving and sometimes heavy as well), then make the U turn and merge right across two lanes of heavy, fast-moving traffic, and ride back along the busy highway a significant distance. 

Most often, no shoulder area is available - that extra space has been used by the J-Turns many turn lanes.  Even when the lane crossings are complete, the bicyclist is still left riding in the travel lane of a busy, fast highway - typically a highway much higher amounts of much faster-moving traffic than was encountered on the minor ride.

The end result is to convert many perfectly viable bicycle routes that use minor roads, which today have perfectly usable intersections with a major highway or two, into routes that most cyclists will not feel safe using.

Formerly usable bicycle routes are now disconnected.

J-Turn major issues for bicycling and walking:

  • Depending on exact situation and details, the J-Turn can add an essentially impassable barrier to bicycle travel on the minor road.  It disconnects a previously connected route for bicycle travel.
     
  • J-Turns do not provide a safe way for pedestrians to cross the roadway
     
  • J-Turns usually replace a crossing with straight-through median opening. These allow reasonable and usable access for people who walk and bicycle. These users can wait for a break in traffic, cross two lanes, reach in the median where they have a refuge that is relatively protected from traffic, and wait there for a break in traffic to cross the remaining two lanes.  This is straightforward, does not require extra travel distance, and is reasonably safe because just two lanes, both moving the same direction, are crossed at once.
    • Replacing this type of intersection with a J-Turn often means that the previously traversable intersection has been replaced by one that is not usable by people who walk or bicycle.
       
    • It is possible to design J-Turn intersections to accommodate bicycling and walking, but we have not seen such a design in Missouri.
       
    • MoDOT's usual response is that these intersections are used only in rural areas where there is "no" pedestrian or bicycle traffic.
       
    • However, there is no step in the planning or design guidance where existing or future pedestrian or bicycle usage or potential demand is actually evaluated. There is simply a blanket assumption that no one walks or bicycles in these rural areas.

Resources:

 

J-Turn Bike-Ped Crossing Diagrams - potential solutions:

 

 

Diagonal Cross. This is the simplest type of crossing. It is designed as a pedestrian crossing, but could be adapted to be usable for both pedestrian and bicycle use.  For the bicyclist, it is awkward in that it requires the bicyclist to cross to the left side of the minor road before crossing the main road.  When crossing the main road, users will be crossing 3-4 lanes of oncoming traffic. Because of the diagonal crossing and additional road width at the turn, the crossing distance is quite long. Many bicyclists will likely be tempted to cross directly from their lane to the median cut - meaning that they are dealing with traffic  coming from both the left and the right.

 

 

Midblock Cross. This idea has potential for use on MoDOT J-Turns.  It can be adapted for bicycling by simply providing wide, bicycleable shoulders on the main highway, extending to the ends of the J-Turn crossovers,  and then a small paved area at the end of the J-turn that can be used as a median refuge area.  The bicyclist coming in on the minor road can turn right and ride the shoulder to the end of the J-Turn.  There the cyclist stops and checks traffic coming from the left, crosses onto the median refuge area, stops to check traffic coming from the right, cross the highway, and returns to the minor road using the provide bicycleable shoulder.

 

This requires riding some extra distance to cross the intersection, but it is simple and has the fewest crossing conflicts and the shortest crossing distance.

It also requires the least additional road work and pavement - only shoulders wide enough for bicycle use on both sides of the road through the main J-Turn area, and possibly small additional paved areas at the end of the J-Turn crossovers.

 

This design is unlikely to be much help for pedestrians.

 

 

 

Direct Cross. This design is simple and provides a short crossing distance.  The median cuts are helpful for both pedestrians and bicyclists who wish to cross.  The crossing distance is fairly short.   The median crossings provide refuges for the user to safely wait for traffic to clear before proceeding with the cross.

 

However, MoDOT's typical median design does not allow the  type of straight-through crossing shown here.  The idea could easily be adapted to MoDOT's design however - perhaps a design similar to this:

 

Possible MoDOT Design #1. This design minimizes crossing distance and conflicts. it minimizes the extra distance pedestrians and bicyclists must travel to cross the intersection.  It allows two refuge areas while crossing.  It can be used by both pedestrians and bicyclists.  It would require minimal change or cost from MoDOT.

 

The dark gray areas would require some type of median cut, pavement, or pavement markings, depending on the  exact design. The green lines could be marked as crosswalks or simply left unmarked.

 

The most problematic area is likely the long crossing of the median, which may run into grade and drainage issues.  

 

 

 

Possible MoDOT Design #2. John White (Tandems of the Ozarks) suggested this possible crossing design.  This is even simpler than option #1 - it requires only one crossing point to be paved, and it is shorter.  This essentially leaves a part of the previous straight-through media crossing in place for the use of people who walk and bicycle.  Barriers can be installed as shown to prevent motor vehicles from taking the straight-through route.

 

 

 

 

 Bicyclist's route through a MoDOT J-Turn

Current bicycle route through a J-Turn. To cross the J-Turn, bicyclists must ride a significant distance on the busy highway, merge across two lanes of traffic, make the U turn, then ride a significant distance back along the busy highway. 

In all J-Turn  implementations we have examined, no shoulder or only a minimal shoulder is provided (even if the road typically has a shoulder, the extra lanes required by the J-Turn configuration use up the shoulder space - meaning that shoulders, if any, usually disappear or are narrowed significantly through the J-Turn area).  So bicyclists will be riding in a lane with 55-65mph traffic as they make this maneuver. 

 

 

 

Possible MoDOT Design #3. By adding shoulders and a small refuge area, bicyclists can ride to the end of the J-Turn area easily, cross two lanes of traffic to the provided median refuge, cross the other two lanes, and return via the provided shoulder.

 

This is a fairly long detour. Because the route is not obvious to bicyclists, this design will require signage to show the intended crossing route. Even with signage, compliance and usage may be low.

 

This design is not much help for pedestrians.

How you can help

 

 Please take a moment to write a public comment to MoDOT and ask them to consider bicycle and pedestrian safety and access on upcoming J-Turn intersection projects:
 

One of the top goals of MoBikeFed's Vision for Bicycling and Walking in Missouri is building a world-class bicycle and pedestrian transportation system in Missouri.  Work to ensure that routine planning and design of the state's road and highway system is safe and usable by people who walk and bicycle is one way we work to reach this goal.

Your membership and generous financial contributions help turn our Vision into reality--building the statewide public support for bicycling, walking, and trails that make major advances like the Rock Island Trail possible.

 
 
Sources: Figures 4.2, 4.5, and 4.7 above are from the North Carolina DOT SuperStreet report. Engineering diagrams are excerpted from MoDOT's Engineering Policy Guide for J-Turns.
 

 
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