Evaluating Crowding in Individual Train Cars Using a Dynamic Transit Assignment Model

• Bakgrund: Many public transport systems are subject to overcrowding, particularly during peak periods. On-board crowding is associated with many negative effects on passengers, such as increased discomfort and stress, unexpected delays and denied boarding, while it can be highly uneven among individual cars of multi-car rail vehicles even during peak hours. There is a general need to reduce crowding effects and improve the system performance and the level of service. Transit assignment models are widely used to model passenger flows in transit vehicles and evaluate on-board crowding effects. However, these models usually do not capture crowding distribution among individual cars, that might lead to underestimation of the generalized travel cost. This motivates our interest in developing a dynamic model to capture on-board crowding in individual train cars and evaluate crowding effects in a more realistic way. The developed model might be useful for public transport operators to evaluate the effect of potential operational or infrastructure interventions at stations during the planning process on on-board crowding unevenness.Metod: A dynamic agent-based public transport operations simulation model, BusMezzo, has been extended in this study for modeling the congestion effects on-board individual cars of the vehicle. Additions to BusMezzo are related to transit network and transit fleet representation as well as dynamic decision making modelling. Each transit stop is divided into a number of sections that is equal to the number of car units that a vehicle consists of and hence, each platform section corresponds to a certain car unit. In modelling individual passengers' travel paths, each passenger makes a sequence of travel decisions, i.e. walking, boarding and alighting decisions, that combined yield to a path alternative. Individual passenger's platform section and car choices are affected by walking and boarding decisions, respectively. The passenger evaluates the alternative platform sections of the stop they want to walk to, considering the walking distance to the platform section and also the total walking distance of the downstream walking links to the destination. When a passenger decides to board a vehicle, they choose the car that corresponds to the selected platform section. Passengers that are denied from boarding the desired car due to car capacity constraints, they stay on the same platform section waiting for other vehicle.Resultat och slutsats: The proposed modeling framework is applied to a case study for the metro network in Stockholm. A train crowding unevenness metric has been introduced to enable easy comparisons between passenger distributions. The effect of the station layout and variations in demand on the crowding unevenness is evaluated. Increased demand level is found to significantly reduce on-board crowding unevenness after they are departing from the most crowded stations. This finding suggests that passenger load is close to train capacity at these stations, leading to lower flexibility of how passengers are distributed among the cars of the train. The closure of the most popular entrance point at a selected station is found to significantly decrease the average unevenness of crowding on-board trains at the departure from the specific station, but also the downstream stations.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Samhällsbyggnadsteknik -- Transportteknik och logistik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Civil Engineering -- Transport Systems and Logistics (hsv//eng)

Publication and Content Type

vet (subject category)

kon (subject category)