PEDESTRIAN ACCIDENT CURES?

Writer Tamara Dean wrote an article on reducing pedestrian accidents. It contained some ideas on slowing traffic down to reduce pedestrian accidents. Here is a table of ways to reduce pedestrian accidents, with utility ratings of effectiveness vs detrimental effects. The first nine are her suggestions.

	METHOD	UT	ADVANTAGES	DISADVANTAGES	DIAGRAM
1	Sidewalks	+5	Gives pedestrians their own space	Need more right-of-way
2	Street Trees	−2	Can protect pedestrians from cars	Can hide pedestrians & bicycles from cars Roots can destroy pavement
3	Roundabouts	+4	Much safer for vehicles & pedestrians	Much more space than normal intersection Must pass all truck traffic
4	Narrower streets	−1	Slows traffic by reducing maneuver space	Must pass large trucks & fire equipment Not suitable for major arterials
5	Speed bumps & humps	−4	Slows traffic with vertical deviations Inexpensive	Painful to passengers with back trouble Can damage bumpers & fenders of some cars High-centers large truck frame resting on hump
6	Chicanes	0	Slows traffic with horizontal deviations	Not suitable for major arterials
7	Bulb-outs	+1	Shorter pedestrian crossing distance	Can keep trucks from turning at intersection
8	Center medians	+3	Pedestrians cross fewer lanes at a time Opposite directions stop at different times Works with flashing pedestrian beacon Pedestrians cross opposite directions of traffic at different times.	Slightly wider street
9	Reduced speed limit	−3	Reduces collision speed Increases maneuvering time	Reduces fuel mileage of vehicles (see below) Some drivers go design speed of road
	METHOD	UT	ADVANTAGES	DISADVANTAGES	DIAGRAM
10	Neckdowns	−1	Only one traffic direction moves at a time	Suitable for only very minor streets
11	Overdesign at 40 mph Sign at 30 mph	−2	Feels safer	Drivers feel higher design speed & drive it Causes some speeding
12	Prohibiting all turns on red	+1	Reduces conflicts at intersection	Reduces fuel mileage of vehicles (see below)
13	Reduced corner curb radii	−2	Shorter paths for pedestrians to cross	Some vehicles must back up to make the turn
14	Isolated Pedestrian Hybrid Beacon	0	Stops traffic for pedestrians	Stops traffic too long (25 s) for one pedestrian Pedestrians often cross before walk signal
15	Intersection Pedestrian Hybrid Beacon	−5	Stops some traffic (not all) for pedestrians	Stops traffic too long (25 s) for one pedestrian Does not stop cross traffic Pedestrians often cross before walk signal Does not conform to  Manual on Uniform Traffic Control Devices
16	Flashing Pedestrian Beacon	+5	Causes minimal interruption of traffic Works well with center median or island	None
17	Removing view blockers	+2	Remove brush, parking, and signs to fix	Might cause owner complaints
18	Pedestrians: educate and enforce	+3	Knowing signal sequences helps pedestrians Pedestrians think their light is next Button does not change signal phase order	Pedestrians do what they can to save time Pedestrians often don't wait for traffic signals Enforcement costs money
19	Bicycles: educate and enforce	+1	Knowing signal sequences helps cyclists Cyclists think their light is next Cyclists need to learn wrong-lane hazards	Cyclists do anything to reduce pedaling effort Cyclists often disobey stop signs and signals Cyclists hate extra blocks for one-way streets Enforcement costs money
20	Motorists: educate and enforce	+4	Motorists need to learn patience	Motorists do what they can to hurry Sometimes they break the law to do so
	METHOD	UT	ADVANTAGES	DISADVANTAGES	DIAGRAM
21	Pedestrian & bicycle overpasses	+1	Free-flow crossings No possibility of collision with a car	Expense of construction and maintenance Some cross at the street to avoid steep ramps
22	Require business signs placed at ground level	−5	Pleases Democrat aesthetics	Hides cars, bicycles, & pedestrians from others Hides driveways from streets
23	Two-way bicycle sidepath on one side of street	−5	Lowest cost for separate sidepaths	Too many conflicts at each intersection Reduced visibility of conflicting traffic
24	One-way bicycle sidepath on each side of street	+4	Minimizes conflicts with bikes Increased visibility of conflicting traffic This is also called "Complete Street"	Costs more to build. Needs more right-of-way
25	Right turn signal if right turn lane and cross left signal	+3	Many right turns happen on Don't Walk Fewer rights during pedestrian Walk	Costs more to install
26	Left and right turns have their own signal phases	+2	Crossing movements never cross paths No lefts or rights during pedestrian walk	Passes less traffic than other methods Needs left and right turn lanes
27	J-turn intersection	+4	Fewer movements at intersection Pedestrians cross fewer lanes Cross only one movement at a time	Higher costs to build Much more right-of-way needed
28	Recall pedestrian phase	−2	Keeps signals in progression Walkers don't have to push buttons	Wastes fuel while vehicle stopped

UT = Utility index  purple line = pedestrians in crosswalk
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SPEEDS AND GAS MILEAGE

Liberals believe that driving slower always increases the fuel mileage of a motor vehicle.

As we shall see, this is not always true:

• The fuel mileage increases as the car goes slower - provided the transmission stays in high gear.
• When the transmission downshifts, the fuel mileage drops by the change in gear ratio.
• This is a major reason why city gas mileage values are lower in EPA ratings.
• Reducing the speed limit by 5 mph makes many cars drive in lower gears, reducing their mileage.

 
The page author regularly drove all of these cars and was able to find out the shift points:

* With the Turboglide transmission (rare)
 This transmission stays in the highest ratio unless acceleration is actually needed.
 The rear axle ratio in this car was chosen for performance, not fuel economy.
 

Yellow - gear at 25 mph.
Green - gear at 30 mph.
Light green - gear for both 25 and 30 mph at minimum throttle.
 

Many electric cars do not have transmissions and are not affected by lower speed limits.

Many hybrid cars do have transmissions and are affected by lower speed limits.

Continuously Variable Transmissions do downshift and so are affected by lower speed limits.

Making any car repeatedly stop or change speed reduces its fuel mileage.