Modeling vehicular and pedestrian delays at signalized midblock crosswalk under mixed traffic conditions

ABSTRACT

The present study aims to develop vehicular and pedestrians delay models for signalized midblock crosswalks under mixed traffic conditions. In this study, the primary data on pedestrian and vehicle flow characteristics were recorded using video-graphic technique. The mixed traffic characteristics and other field conditions were simulated in the Vissim micro-simulation tool. The traffic flow characteristics were calibrated and validated using GEH statistics, which came out to be 2.5. For modeling the pedestrian and vehicle delays, several scenarios were simulated by varying the traffic flow and traffic signal characteristics. For each scenario, the simulated delay values were recorded. Considering the data set simulated, the delay models were developed using multiple linear regression technique with 10-fold cross validation. These models were then validated which yielded an error (MAPE) of 17% and 13% in estimating pedestrian and vehicle delays respectively. These models can be used as a tool designing better pedestrian facilities at signalized midblock crosswalks.

KEYWORDS:

• Controlled midblock crosswalks
• pedestrian delay
• vehicular delay
• delay models
• micro-simulation

Acknowledgments

The authors thank the Traffic Police Department, Hyderabad, India for their assistance in collecting field data. The authors also thank the Ministry of Education, Government of India for the financial support in the form of stipend given to the research scholars through centrally funded institutes in India.

Disclosure statement

No potential conflict of interest was reported by the author(s).

DATA AVAILABILITY STATEMENT

Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.https://drive.google.com/file/d/1kS53JWXH10Q3MGIxgBX2KEd0eMPvGCJZ/view?usp=sharing

Notations

The following symbols are used in this paper:

D_V = Vehicular Crossing delay (Sec/veh);

D_q = Vehicular queuing delay (Dec/veh);

D_P = Pedestrian delay (sec/ped);

C = cycle Length;

G = Pedestrian green phase;

G_e = effective green time of vehicle (sec);

(g/C) = Green ratio;

N = number of vehicles crossing the stop line during effective green time;

n = number of five-second intervals;

q = Vehicular volume (veh/h);

S = saturation flow (veh/hr of green);

C_a = Capacity of lane group (Veh/h);

X = degree of saturation (v/C);

K = incremental delay factor (0.50 for pretimed signals);

I = upstream filtering adjustment factor (1 for an isolated intersection);

T = evaluation time;

D_g = Delay during green phase;

K_nt = correction factor for non-uniform arrival rate;

R_E = Effective red time (sec);

K_C = the ratio of number of pedestrians complying with signal to the number of pedestrians arriving at the non-green phase;

nt = total number of pedestrians;

ng = number of pedestrians arriving during the green phase;

α₁=Correction factor for non-uniformity arrival rate;

α₂= fraction of pedestrians who cross during non-green phase;

γ = Correction factor for pedestrian actual crossing time

P = Time gap between pedestrian start crossing and 1^st vehicle reaching the conflict point. [12]