1A. Introduction. TFGAP features five signals for pedestrians crossing the street:

Signal			Pedestrians who are already crossing ...	Pedestrians who are waiting to cross ...	Right of Way	Next Signal
SWP	Steady White Person		may continue to cross	are encouraged to begin	motorists yield to pedestrians	FWP
FWP	Flashing White Person		may continue to cross	are encouraged to wait	motorists yield to pedestrians	SVT SOH
SVT	Steady Violet Triangle		may continue to cross, as the way is clear	are encouraged to begin, if the way is clear	pedestrians yield to motorists	FVT
FVT	Flashing Violet Triangle		may continue to cross, as the way is clear	are encouraged to wait	pedestrians yield to motorists	SOH
SOH	Steady Orange Hand		should have already completed	must wait	n/a	SWP SVT

MUTCD section 4E currently specifies the flashing orange hand (FOH) for clearance of the protected crossing, and offers no signal for any kind of permissive movement.

TFGAP introduces the SVT (which resembles a YIELD sign) for the permissive crossing, along with distinct signals for protected and permissive clearance, the FWP and FVT respectively. Not workable would be to retain the traditional FOH, if it is to be used for clearance of both the protected and permissive crossing: such arrangement would mean that after clearance starts, pedestrians in the crosswalk would have no reminder of who must yield to whom. Also, motorists who arrive after clearance begins would be unable to learn anything about the right-of-way situation by looking at the pedestrian signals.

1B. Importance of Protection. TFGAP calls for every intersection that has pedestrian signals to routinely offer a protected phase to those on foot. The permissive cycle is merely an "extra" to be scheduled when opportune. An intersection that never offers protected crossing is inadequate for several reasons:

• Some pedestrians have visual disabilities, and have difficulty seeing approaching cars.
• Some children have not yet learned how to judge gaps in traffic, and will have been instructed by their parents to "wait for white".
• Traffic will sometimes be heavier than planners expected, and there may be no safe gaps at all.

1C. Applications of the Permissive Signals. The violet triangles should be installed only where where traffic lights for motorists are simple. Otherwise, pedestrians will have difficulty figuring out from what directions cars might be coming. This is doubly true because pedestrians often cannot even see all the vehicular signals.

Perhaps the best places for early installations of the permissive signals are mid-block crosswalks, because yielding pedestrians need worry about approaching vehicles from only two directions. In particular there are no concerns about turning cars. The signal could in fact cycle SVT-SWP-FWP, omitting the SOH and FVT entirely.

2A. General. Pedestrian clearance contrasts greatly with motorist clearance:

• The main factor in calculating motorist clearance time at an intersection is the expected speed of the approaching drivers, because the light must stay yellow for enough seconds that a motorist has enough distance to stop. Once the driver has entered an intersection, the time required for her to complete passage is generally minimal.
• With pedestrians, stopping distance is of no concern. Instead, clearance time is based upon the expected speed of the pedestrian as she walks across the street.

MUTCD section 4E.10 recommends that clearance time be calculated assuming that pedestrians travel 1.2 meters per second. However, this is only a compromise figure:

• Brisk walkers can reach twice that speed and runners thrice. These travelers will be inconvenienced by a clearance signal that begins -- from their point of view -- several seconds too early, as it will sometimes cause them to needlessly wait through most of a cycle of signals.
• Some pedestrians travel slower than 1.2 m/s. Those persons may feel endangered if they are still in the street when conflicting vehicles receive a steady green dot, particularly if those vehicles start edging into the crosswalk.

2B. Current Practice. The MUTCD, in section 4E.07, contains the seed of a more flexible clearance system by allowing a countdown signal, which is a numerical display showing the number of seconds remaining in the clearance interval. Orange numerals are displayed whenever the FOH is displayed, but the numerical section is dark whenever the SOH or SWP appear. The FOH changes to the SOH precisely when the count reaches zero. Here is a portion of the sequence:

According to some reports, the traditional pedestrian clearance signal (the FOH) is often misinterpreted, and pedestrians who are still crossing when clearance starts may falsely believe that they have done something wrong. The countdown signal is a way to offer reassurance to these pedestrians, particularly if the R10-3e educational sign is installed. MUTCD figure 2B-18 pictures this and related signs.

Although pedestrians are not supposed to start crossing after the countdown (hence the clearance interval) has begun, some runners and fast walkers will nonetheless proceed "unofficially", because they have become familiar with countdown signals and can estimate, from the number of lanes in the road, how long they will need to cross the street in an ostensibly safe manner. From this practice arises the proposal of the next section.

2C. Extending the Countdown. Under TFGAP, countdown signals are never required. When used however, the countdown need not begin at the onset of clearance but should start earlier, during the regular crossing phase. Pedestrians would be permitted to begin crossing the street with any number of seconds remaining, but would be expected to complete their passage before the count reached zero. (As always, no one should be in the crosswalk when the SOH is illuminated.)

The change from the SWP to the FWP, or the SVT to the FVT, would be only advisory, of primary benefit to those pedestrians unfamiliar with countdown signals in general or the configuration of one intersection in particular. There is no great need for the number to flash during clearance, so the diagrams below depict the number as steady.

For example, at a street 15 meters wide engineers might calculate that 13 seconds of clearance time are sufficient for most pedestrians; the engineers consequently program the pedestrian signals to start flashing when the countdown reaches 13. This might be done with either protected signals:

or permissive ones:

Since crossing permissively is more difficult than crossing protectedly, engineers might decide that permissive clearance requires a few more seconds than protected clearance.

2D. Countdown Details. Some signal controllers can skip phases when no traffic is approaching from some direction. When this happens, a permissive signal might extemporaneously be upgraded to protected while the countdown is in progress, as during the regular phase:

or the clearance phase:

Some signal controllers operate not according to a simple timer, instead relying on vehicle and pedestrian detectors to adjust phase scheduling as volume fluctuates. Under the most dynamic algorithms the controller, at the moment that the SWP phase begins, might not yet have the information to calculate the signal's duration. As a result, the countdown cannot begin.

TFGAP recommends that the numerical section of the signal remain dark until the controller has determined exactly when pedestrian crossing will end. This way, any numbers displayed will be accurate. As an alternative, it is possible to devise some special symbol to announce that a countdown is forthcoming. However, there is minimal need because numerical displays are never required, and pedestrians will already have either an SWP or SVT to look at. Plus, every new symbol requires educational efforts.

2E. Option: Countdown During the SOH. Pedestrians, wanting to cross a street, who push a signal's activation button are often skeptical that the equipment is working properly. For this reason, some buttons now include a small lamp activated by the controller when it learns that the button has been pushed. This gives pedestrians a measure of assurance that the signals are working properly. Such verification may encourage those on foot to wait until they receive some sort of WALK signal (i.e. SWP or SVT), instead of impatiently crossing in violation of the SOH.

Another way to achieve the same effect is to display orange countdown numerals during the SOH, informing pedestrians of how much longer they must wait.