B-Line Trail Morton
College
College
Walnut
Washington
Washington
Lincoln
Grimes
Grimes
Dunn
Indiana
Fess
Park
Park
Woodlawn
The 7-Line was built on Seventh Street between the B-line trail (near Morton Street) and Woodlawn Avenue. It was the liberal ideal of what a complete street for cars, bicycles, and pedestrians should be like.
This was supposed to be the bicyclist's ideal: a bikeway where the rider does not have to stop for other traffic for most if its length. Only at the traffic signals at College and Walnut did the cyclist have to stop.
Now they want to build another of these monstrosities on Second Street.
The city stupidly built a two-way bikeway along the south edge of Seventh Street. This caused the following problems:
This design causes hidden conflicts where two drivers cannot see the other until it is too late.
The 7-Line looks like it was designed by an idiot cyclist with the belief that bicycles should never have to stop.
We learned the Five Rules of Right-of-Way when we learned to drive. They are:
Traffic control devices can supersede some of these rules by assigning right-of-way.
Traffic comes from unexpected directions:
Failure of the Five Rules of Right-of-Way to handle all of the movements here causes the extra accidents.
Refer to the diagram at right and the blue arrows.
This can also happen if the blue truck is not there, because each vehicle is in the other vehicle's blind zone
There are at least 6 different combinations of bicycle and car movements that can cause this kind of hazard.
Here are other factors that make the danger worse.
Notice that all of the wrong ways of building bicycle lanes and sidepaths create unexpected conflicts, bring vehicles in from unexpected directions, or hide various traffic movements from each other. These dangers must be avoided.
None of these wrong ways of adding bicycle lanes or paths conforms to the normal laws governing lane use and right-of-way.
None of these wrong ways of adding bicycle lanes or paths conforms to the Manual of Uniform Traffic Control Devices.
Adams Street
Adams Street
Complete Streets Intersection
These separated bike lanes are on Adams Street between Kirkwood Avenue and Third Street. It is the correct way to add separated bike lanes to a street.
Beauty is fitness expressed:
- The 7-Line looks awful from the driver's seat and from the air.
- It also does not work very well.
- But the Adams Street installation and the Complete Street look very nice.
- They also work well.
Most drivers do not have this expanded table, and many do not see how many movements are in a 7-Line intersection.
At a traffic signal, there is little trouble. But the driver needs to know that the bikeway is two-way.
At an all-way stop, there is little trouble. But the driver needs to know that the bikeway is two-way.
At an intersection where only one street stops, the new table is essential, as is knowing that the bikeway is two-way.
STANDARD 4-WAY INTERSECTION | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Drivers who drive logically usually have some kind of overlap table similar to the one at right.
This table can be approached from any side.
- Each large circle symbol is at the crossing of two traffic movements - a traffic conflict.
- Movements are: E-W thru N-S thru E-W left N-S left all rights 12 movements total
- Means that the two movements that cross at the symbol cannot
go at the same time.
12 absolute conflicts total
- Means that the two movements that meet at the symbol cannot
go at the same time,
- unless there is a special merge lane to accept turning vehicles.
4 merge conflicts total
- Means that the two movements that cross at the symbol cannot
go at the same time,
- but the turn can go permissively through gaps in the straight movement if allowed.
8 permissive conflicts total
- Means that the two movements diverge.
- They do not normally conflict unless they get in each other's way by queueing.
12 diverging conflicts total (not shown in upper table)
- Is a median dividing bollard.
- If there is no symbol because the two movements do not meet, then the movements can overlap in time.
- They can go at the same time.
36 total conflicts
If the intersection has only 3 legs, this table can be used by putting no traffic on the 4th leg.
STANDARD 4-WAY INTERSECTION - SINGLE APPROACH | |||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Entry | YOUR LEG | PED | AHEAD LEG | PED | LEFT LEG | PED | RIGHT LEG | PED | |||||||||
↕ | ↕ | ↔ | ↔ | ||||||||||||||
This table is approached from the left end.
Movements that do not involve the left end approach are not shown.
The meanings of the circles are the same as above.
This table could be turned so the left end is down to match what the driver sees in front of his car.
7-LINE 6-WAY INTERSECTION | ||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Most drivers do not have a table to cover this mess. Most would not expect such an intersection.
This table must be rotated to fit the orientation of the intersection.
- Each large circle symbol is at the crossing of two traffic movements - a traffic conflict.
- Motor Vehicle Movements are:
E-W thru N-S thru
E-W left N-S left
all rights 12 movements total
- Bicycle Movements are:
E-W thru N-S thru
E-W left N-S left
all rights 12 movements total
Grand Total 24 movements
- Means that the two movements that cross at the symbol cannot
go at the same time.
24 absolute conflicts total
- Means that the two movements that meet at the symbol cannot
go at the same time,
- unless there is a special merge lane to accept turning vehicles.
8 merge conflicts total
- Means that the two movements that cross at the symbol cannot
go at the same time,
- but the turn can go permissively through gaps in the straight movement if allowed.
16 permissive conflicts total
- Means that the two movements diverge.
- They do not normally conflict unless they get in each other's way by queueing.
24 diverging conflicts total (not shown in upper table)
- Is a median dividing bollard.
- If there is no symbol because the two movements do not meet, then the movements can overlap in time.
- They can go at the same time.
72 total conflicts
FIRST 4-WAY INTERSECTION - SINGLE APPROACH TABLE | |||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Entry | YOUR LEG | PED | AHEAD LEG | PED | LEFT LEG | PED | RIGHT LEG | PED | |||||||||
↕ | ↕ | ↔ | ↔ | ||||||||||||||
SECOND 4-WAY INTERSECTION - SINGLE APPROACH TABLE | |||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Entry | YOUR LEG | PED | AHEAD LEG | PED | LEFT LEG | PED | RIGHT LEG | PED | |||||||||
↕ | ↕ | ↔ | ↔ | ||||||||||||||
The trick is to mentally cut the intersection in two with the bikeway on one side and the motorcarway on the other.
This trick requires the driver's brain to be able to allow a process to use (call) itself with different information.
The 4-way intersection single approach table is discussed above.
The 6-way 7-Line intersection is still difficult to drive. These tricks make it a little easier.