Width alone does not rank accuracy. A and B use a common density target; C uses a separate perception target. B includes a whole-lane implementation rule.
LOS A–F comparison
Same demand, different declared targets
Minimum-width constraints and whole-lane increments can produce equal final widths for different LOS profiles. LOS F is diagnostic, not a recommended design.
The smallest tested width that satisfies the selected criteria.
Wclear = round upincrement { max [ Wminimum, max(Wselected models) + Wedge loss ] }
No averaging of model outputs. No automatic claim of global optimality, safety improvement or legal compliance. The search is one-dimensional and limited to the declared width grid and ceiling.
Effective width = clear walk zone minus declared edge loss. Total cross-section = clear walk zone + frontage + furniture/utility zone + curb. Physical obstructions inside a walk zone need a segment-level survey; this calculator does not simulate them.
A
Weidmann · flow-density model
v(k) = vf[1 − exp{−γ(1/k − 1/kj)}]; We = Q / [k × v(k)]. The width expression is a continuity-based derivation, not a new published equation.
Weidmann (1993), Transporttechnik der Fussgänger, IVT report 90, ETH Zürich. Equation and reference values reproduced in Hänseler et al. (2013), An aggregate model for transient and multi-directional pedestrian flows in public walking areas, EPFL report 131219, Equation 1, printed p. 7.
The published Equation 10 supplies queue-based speed. This implementation combines it with Q = kWv (Equation 2), enumerates integer lane counts, and sets W = b × s. It is not a direct use of Equation 15, and its service rate R is not substituted for observed demand.
Rahman et al. (2013), Modelling Pedestrian Travel Time and the Design of Facilities: A Queuing Approach. PLOS ONE, 8(5), e63503. DOI: 10.1371/journal.pone.0063503. Its steady-state, uninterrupted-flow and virtual-lane assumptions need review for each application.
Queue equation & numerical implementation
x = k/kj; G = xs / [ s(1−x/s)xs + s(s!)(1−x/s)2 Σn=0…s−1(xn/n!) ]; v = vf/(1+G)
Equivalent Erlang-B/Erlang-C recursion avoids factorial overflow. Unused fractional lane width is not credited. The lane parameter is a movement allowance, not an anthropometric body diameter.
I = −1.7592 − 0.2299P + 1.3240N0.1 − 0.0196We2 + 0.5447C0.1. Solve for We using the selected I target. Equation 6.1 is used because the input is a fixed sidewalk count N per five minutes, not Equation 7.5's street-wide allocation.
Carvalho (2006), Um modelo para dimensionamento de calçadas considerando o nível de satisfação do pedestre. Doctoral thesis, University of São Paulo. Equation 6.1, printed pp. 108–109; service mapping, Table 7.9. P = 0 peak / 1 off-peak. I = 0.49 means 49% in the original coding.
Uncalibrated transfer to Philippine sidewalks is not established. Its illustrative 1–4 m nomogram is not an independently validated applicability range. Satisfaction LOS is not HCM operational LOS.
Space values are project-selected representative points within historical HCM 2000 space bands, not the full LOS method. Context: FHWA-HRT-05-137 (2006), Chapter 2, Table 4. The source describes severely restricted movement at F; it is not accepted here as a design recommendation.
C's separate A–E dissatisfaction targets follow the limits reported in Carvalho's Table 7.9; 75% for F is an explicit illustrative project choice. Coupling both targets to one selector is a workflow choice, not evidence that operational and perception LOS are equivalent. Changes in model widths can be masked in the final width by minimum clear-width constraints or lane increments.
These profile assignments are not calibration. Local calibration needs observed performance data and parameter fitting; independent validation remains necessary.
Before a thesis recommendation becomes a design decision
Verify pedestrian counts, interval normalization, forecasting assumptions and observed speeds.
Specify the HCM edition and evaluation method separately. The A–F profiles do not certify LOS. Manual edits to space or dissatisfaction are recorded as Custom.
Replace the project minimum with the applicable documented accessibility/local requirement. This prototype does not assess ramps, slopes, tactile paving, drainage or utility feasibility.
Assess local model fit with independent observations and sensitivity tests. Published validation elsewhere does not validate this implementation or its recommendation locally.
The selected-model envelope is a project decision rule, not a formula published by any of these authors. A conservative envelope is not automatically more accurate.