Traffic Signal Timing for Pedestrians
45 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the average walking speed of pedestrians mentioned in the content?

  • 2.0 ft/s
  • 4.5 ft/s (correct)
  • 5.0 ft/s
  • 3.0 ft/s

The MUTCD specifies an exact duration for slow crossers to begin crossing.

False (B)

What formula is used to calculate the clearance time needed for pedestrians to cross an intersection?

FDW + feff > D/S_p1

The default primary design speed for pedestrians is __________ ft/s.

<p>3.5</p> Signup and view all the answers

What is the suggested clearance time for crosswalks based on the example provided?

<p>20 s (B)</p> Signup and view all the answers

Match the walking speed specifications with their corresponding descriptions:

<p>3.0 ft/s = Walking speed for seniors or young children 3.5 ft/s = Default primary design speed 4.0 ft/s = Previous primary pedestrian design speed 4.5 ft/s = Average walking speed of pedestrians</p> Signup and view all the answers

Longer clearance times should be provided when there are many pedestrians.

<p>True (A)</p> Signup and view all the answers

What is the recommended walking speed in European countries such as the Netherlands?

<p>4 s for crossing time</p> Signup and view all the answers

What is a leading pedestrian interval (LPI) designed to do?

<p>Mitigate conflicts with turning vehicles (C)</p> Signup and view all the answers

Pedestrian crossing islands must be at least 8 feet deep and equipped with pedestrian signals.

<p>False (B)</p> Signup and view all the answers

What is the average delay for a three-stage crossing studied in the Boston area?

<p>over 120 seconds</p> Signup and view all the answers

What is the recommended minimum length for the Walk interval according to the MUTCD?

<p>7 seconds (D)</p> Signup and view all the answers

The Flashing Don't Walk indication allows pedestrians to start crossing during a red clearance.

<p>False (B)</p> Signup and view all the answers

The crossing islands must be at least __ ft deep.

<p>6</p> Signup and view all the answers

Match the following characteristics with their descriptions:

<p>Pedestrian Refuge Island = A safe area for pedestrians to wait while crossing Multistage Crossing = A crossing requiring pedestrians to wait between stages LPI = An interval that allows pedestrians to start crossing before vehicles get a green light Median Crossing = A crossing where the median does not need to be a refuge</p> Signup and view all the answers

What is the best timing option for pedestrians if a longer Walk interval is desired?

<p>Option A</p> Signup and view all the answers

The ________________ is displayed when pedestrians should not start crossing but may continue if they have already begun.

<p>Flashing Don't Walk</p> Signup and view all the answers

Match the following pedestrian indications to their meanings:

<p>Walk = You may start to cross Flashing Don't Walk = Don't begin, but if you've begun, continue crossing Don't Walk = Solid orange hand indication Pedestrian phase end buffer = Time to safely finish crossing after FDW ends</p> Signup and view all the answers

What is the primary Standard for pedestrian start time in most of the US?

<p>7 seconds (D)</p> Signup and view all the answers

Which option results in the shortest Walk interval for pedestrians?

<p>Option B (C)</p> Signup and view all the answers

Pedestrians are legally supposed to start crossing only during the FDW interval.

<p>False (B)</p> Signup and view all the answers

The total length of FDW and the pedestrian phase end buffer must accommodate a pedestrian who started walking right at the end of the Walk interval.

<p>True (A)</p> Signup and view all the answers

What does 'Weff' represent in pedestrian timing?

<p>Effective Walk interval length</p> Signup and view all the answers

What is the purpose of the pedestrian phase end buffer?

<p>To provide safe time for pedestrians to finish crossing.</p> Signup and view all the answers

The first ____ seconds of the pedestrian phase end buffer should be considered effective.

<p>3</p> Signup and view all the answers

Match the following pedestrian timing terms with their descriptions:

<p>Effective Walk = Length W + 4 Primary standard = Seven seconds to start Secondary standard = Two seconds to start Phase end buffer = Transition time after the Walk signal</p> Signup and view all the answers

Which of the following describes the 'effective pedestrian phase end buffer'?

<p>Only the first 3 seconds are effective (A)</p> Signup and view all the answers

There is a mandated limit on the maximum length of the pedestrian phase end buffer.

<p>False (B)</p> Signup and view all the answers

What time is mandated by the MUTCD for pedestrian phase end buffer minimum?

<p>No specific time is mentioned; there is a minimum but no maximum.</p> Signup and view all the answers

What is the default design speed for slower pedestrians according to the MUTCD's requirement?

<p>3.0 ft/s (C)</p> Signup and view all the answers

The secondary clearance requirement does not need to be satisfied if the primary crossing standard is met.

<p>True (A)</p> Signup and view all the answers

What should be adjusted if the secondary requirement is not met and the crossing length is longer than 105 ft?

<p>Increase W</p> Signup and view all the answers

The pedestrian phase timing includes Walk interval (W), _____, and buffer.

<p>FDW</p> Signup and view all the answers

Match the following pedestrian timing methods to their corresponding actions:

<p>First = Set pedestrian phase end buffer Second = Set FDW Third = Calculate remainder for W Fourth = Check secondary clearance</p> Signup and view all the answers

What is the minimum value for the Walk interval (W) when setting lengths for concurrent crossings?

<p>7 seconds (A)</p> Signup and view all the answers

In Option A, how much effective walk time do pedestrians get during the comparison of alternative pedestrian timings?

<p>20 seconds</p> Signup and view all the answers

All pedestrian intervals in non-concurrent crossings are set equal to their maximum values.

<p>False (B)</p> Signup and view all the answers

Which option best serves pedestrian needs at a crossing?

<p>Having a longer Walk interval (B)</p> Signup and view all the answers

The pedestrian phase should always prioritize vehicular timing needs.

<p>False (B)</p> Signup and view all the answers

What does FDW represent in the context of pedestrian timing?

<p>Phase end buffer</p> Signup and view all the answers

The minimum split needed for vehicles is given by the equation minSplitveh = Gneeded + Y + Rc. Here, Y represents the _____ time.

<p>yellow</p> Signup and view all the answers

Match the pedestrian and vehicle timing needs with their appropriate expressions:

<p>MinSplit<del>veh</del> = G<del>needed</del> + Y + R<del>c</del> MinSplit<del>ped</del> = W<del>min</del> + FDW + ff Walk Interval = minSplit<del>veh</del> -- FDW -- phase end buffer Split = max (minSplit<del>veh</del>, minSplit<del>ped</del>)</p> Signup and view all the answers

What condition allows the pedestrian movement to govern the phase length?

<p>When minSplit<del>veh</del> is less than minSplit<del>ped</del> (C)</p> Signup and view all the answers

A standard Walk interval of 7 seconds is always sufficient for pedestrian crossings.

<p>False (B)</p> Signup and view all the answers

What is the minimum walking interval, W~min, for pedestrian timing under normal conditions?

<p>7 seconds</p> Signup and view all the answers

Flashcards

Signalized Crosswalk Timing

Timing of pedestrian signals at intersections, considering concurrent vehicle phases.

Pedestrian Phase Options (A, B, C)

Different ways to time pedestrian crossings within a vehicle phase; Option A- longest Walk; Option B - shorter Walk due to restrictions; Option C - minimum pedestrian timing.

Pedestrian Signal Indications

Walk, Flashing Don't Walk (FDW), and Don't Walk.

Walk Interval

Time when pedestrians can start crossing safely.

Signup and view all the flashcards

Flashing Don't Walk (FDW)

Pedestrian signal indicating that pedestrians can finish but cannot start crossing.

Signup and view all the flashcards

Don't Walk Signal

Pedestrian signal indicating that pedestrians must not start crossing.

Signup and view all the flashcards

Pedestrian Phase End Buffer

Interval after FDW ends to allow those who started crossing to finish safely. MUTCD mandates 3 seconds.

Signup and view all the flashcards

Minimum Walk Interval

Shortest permitted time for the Walk signal, recommended as 7 seconds, but can be as short as 4.

Signup and view all the flashcards

Pedestrian Design Speed

A speed used for designing pedestrian signals, considering average walking speeds and population demographics. It determines how much time is needed for pedestrians to cross an intersection safely.

Signup and view all the flashcards

Primary Design Speed

The default speed used for designing pedestrian signals for general pedestrians, currently 3.5 ft/s (about 2.4 mph).

Signup and view all the flashcards

Secondary Design Speed

A slower design speed used for pedestrians who are slower, such as seniors or young children. This is often set to 3.0 ft/s.

Signup and view all the flashcards

Effective Phase End Buffer

A time period added to the end of the flashing Don't Walk (FDW) signal. It allows those who started crossing during FDW to finish safely, ensuring no one gets stuck in the middle. The default is 3 seconds.

Signup and view all the flashcards

Pedestrian Clearance Needs

The time pedestrians need to safely cross an intersection, determined by the crosswalk length and pedestrian walking speed.

Signup and view all the flashcards

Crosswalk Length

The distance pedestrians must cover from the curb to the far side of the traveled way, including any parking lanes or shoulders included in the crosswalk.

Signup and view all the flashcards

MUTCD

The Manual on Uniform Traffic Control Devices, a guide that establishes standards for traffic control devices, including pedestrian signals.

Signup and view all the flashcards

Effective Walk Interval

The actual time pedestrians can safely cross, considering that they may start during the Flashing Don't Walk (FDW) interval. It's calculated by adding 4 seconds to the Walk interval.

Signup and view all the flashcards

Effective Pedestrian Phase End Buffer

The initial part of the Pedestrian Phase End Buffer (about 3 seconds) where pedestrians feel comfortable finishing their crossing since conflicting traffic is usually released after 3 seconds.

Signup and view all the flashcards

Why is there a Pedestrian Phase End Buffer?

To provide enough time for pedestrians who started crossing during the Walk or FDW interval to safely complete their crossing before conflicting traffic is released.

Signup and view all the flashcards

Primary Pedestrian Timing Standard

The standard that recommends a 7-second Walk interval to allow pedestrians sufficient time to start crossing. However, a shortened 4-second Walk interval is allowed.

Signup and view all the flashcards

Secondary Pedestrian Timing Standard

This standard suggests a 2-second Walk interval, typically used in situations where pedestrians have less time to begin crossing.

Signup and view all the flashcards

What happens if the Pedestrian Phase End Buffer is too short?

Pedestrians may feel rushed to finish their crossing since they know conflicting traffic might be released soon. This can lead to anxiety or unsafe rushing.

Signup and view all the flashcards

Why is there a difference between the Effective Pedestrian Phase End Buffer and the Pedestrian Phase End Buffer?

While the Pedestrian Phase End Buffer is technically the entire interval after the FDW, the effective portion represents the first 3 seconds where pedestrians feel safe to continue crossing. The rest of the interval provides no additional safety benefit for pedestrians.

Signup and view all the flashcards

Leading Pedestrian Interval (LPI)

A period of time where pedestrians have a Walk signal before vehicles are allowed to turn, allowing them to start crossing before any turning traffic.

Signup and view all the flashcards

Pedestrian Refuge Island

A physical island in the middle of a crossing that allows pedestrians to stop and wait between stages of the crossing.

Signup and view all the flashcards

Multistage Crossing

A crossing divided into multiple stages, with pedestrians waiting at a refuge island between stages.

Signup and view all the flashcards

Minimum Depth of Refuge Island

A safety requirement for pedestrian refuge islands, mandating a minimum depth of 6 feet for safe pedestrian use.

Signup and view all the flashcards

Physical Median as a Crossing

A road with a physical median can be designed for pedestrians to cross in a single pass without a refuge island.

Signup and view all the flashcards

Secondary Clearance Requirement

Ensures that pedestrians have enough time to cross the street safely after the "Flashing Don't Walk" signal starts, especially for wider crossings.

Signup and view all the flashcards

Primary Crossing Standard

The main requirement that determines the minimum time needed for pedestrians to safely cross a street.

Signup and view all the flashcards

Concurrent Crossing

A pedestrian crossing that happens at the same time as a vehicle phase, meaning the signals for both pedestrians and vehicles are active simultaneously.

Signup and view all the flashcards

Setting W and FDW

Choosing the lengths of the Walk interval (W) and Flashing Don't Walk interval (FDW) for a safe pedestrian crossing.

Signup and view all the flashcards

Working Backwards in Time

When setting pedestrian intervals in a concurrent crossing, start with the end buffer and work backward to determine Walk interval time.

Signup and view all the flashcards

Checking the Secondary Standard

After setting Walk and FDW intervals, confirm that they meet the secondary clearance requirement, especially for long crossings exceeding 105 ft.

Signup and view all the flashcards

Minimum Split for Vehicles

The shortest time needed for a vehicle phase, calculated as the sum of the green time, yellow time, and clearance time.

Signup and view all the flashcards

Minimum Split for Pedestrians

The shortest time needed for a pedestrian phase, calculated as the sum of the minimum Walk interval, the flashing "Don't Walk" time, and the final clearance time.

Signup and view all the flashcards

Split

The total time allocated to either the vehicular phase or the pedestrian phase in a signal cycle. Whichever phase needs more time governs the overall split.

Signup and view all the flashcards

Vehicle Timing Governs

When the minimum split needed for vehicles is greater than the minimum split needed for pedestrians, the pedestrian phase fits within the vehicle phase. The Walk interval is adjusted to match the vehicle split.

Signup and view all the flashcards

Pedestrian Timing Governs

When the minimum split needed for pedestrians is greater than the minimum split needed for vehicles, the vehicle phase fits within the pedestrian phase. The vehicle timing is adjusted to match the pedestrian split.

Signup and view all the flashcards

Why are longer “Walk” intervals better for pedestrians?

Longer "Walk" intervals ensure pedestrians have more time and fewer delays to cross safely, resulting in better pedestrian service and safety.

Signup and view all the flashcards

Study Notes

Signalized Crosswalk Timing

  • Traffic signals benefit both vehicle and pedestrian traffic.
  • Most signalized crossings run concurrently with a vehicle phase.
  • Figure 4-1 details three options for pedestrian timing within the vehicle phase.
  • Option A: Maximizes Walk interval within the vehicle phase split.
  • Option B: Includes common restrictions resulting in a shorter Walk interval (6 seconds shorter).
  • Option C: Minimum pedestrian timing as required by the MUTCD.

Pedestrian Indications and Functional Intervals

  • Pedestrian signals have three indications (Walk, Flashing Don't Walk, Don't Walk).
  • Pedestrian timing has four intervals.
  • Walk: White walking man, signals that crossing is permitted. MUTCD recommends 7 seconds minimum.
  • Flashing Don't Walk (FDW): Flashing orange hand, pedestrians should not begin crossing, but continue if they have already started.
  • Don't Walk (DW): Solid orange hand; displayed during two intervals, from FDW end to when conflicting traffic is released.

Effective Pedestrian Intervals

  • Pedestrians are permitted to start crossing during the first few seconds of FDW.
  • Effective Walk interval (Weff) = Walk interval (W) + 4.
  • Effective Pedestrian Buffer (feff) length: Minimum 3 seconds. No limit on maximum feff.
  • First 3 seconds of feff considered the Effective Pedestrian Buffer in practice.

Pedestrian Start Time Needs

  • Primary standard: 7 seconds to start crossing (4 seconds allowable).
  • Secondary Standard: 2 seconds to start crossing.

Pedestrian Clearance Needs

  • Crossing time calculation: Crossing length (D) divided by walking speed.
  • Pedestrian signal timing speed options:
    • Sp1 = 3.5 ft/s (general pedestrians)
    • Sp2 = 3.0 ft/s (slower pedestrians)
    • Average pedestrian speed ~ 4.5 ft/s

Setting Walk and FDW Interval Lengths

  • Pedestrian intervals (W, FDW, buffer) are set to minimum values.
  • These intervals follow the primary crossing standard, and can be adjusted to meet secondary standards.

Pedestrian Timing Needs vs. Vehicle Timing Needs

  • Pedestrian Phase Length is governed by Vehicle Timing when the Vehicle phase is long enough to accommodate a Pedestrian phase.
  • Pedestrian Phase Length is governed by Pedestrian Timing needs when the pedestrian crossing needs more time than the vehicle movement.

Leading Pedestrian Interval (LPI)

  • Used in situations where concurrent pedestrian and right-turning vehicles may conflict.
  • Full Protection: Separate pedestrian phase from right-turn phase.
  • Partial protection (LPI): Gives pedestrians a head start (several seconds) to establish priority before right-turning vehicle conflict.
  • Typical values: 3 to 7 seconds.

Other Aspects of Pedestrian Crossings

  • Crossings can be broken into stages with refuge islands (pedestrian islands), with pedestrian signals.
  • Multi-stage crossings can result in excessively long delays.
  • Crossings can exist in single passes where a road has a physical median which may be optional.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Furth's Traffic Engineering Notes on Pedestrian Timing (PDF)

Description

Explore the nuances of signalized crosswalk timing and pedestrian indications. This quiz covers different options for pedestrian timing within vehicle phases, as well as the various signals indicating when pedestrians can safely cross. Test your understanding of these essential traffic management concepts.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser