Public Transit

Influence of weather on bus ridership


flickr photo shared by Reasonable Excuse under a Creative Commons ( BY-NC ) license

It's going to be another warm week here in Berkeley, as the Summer unofficially begins. A new article, "The influence of weather on local geographical patterns of bus usage" by Sui Taoa, Jonathan Corcoranb, Mark Hickmana, and Robert Stimsonc, in the Journal of Transport Georgraphy that looks at how weather patterns affect bus ridership. 

This paper broadens the research on weather and public transport usage by considering the micro dynamics of the effect that various weather conditions impose on micro geographic patterns of bus ridership in Brisbane, Australia. A smart card data set and detailed measurements of weather, allied with a suite of statistical and visual analytic techniques, are employed to capture the effect of weather on the local variations of bus ridership. While changes in weather conditions do not significantly affect bus ridership at the system level, some marked influence was found for rainfall, wind speed and relative humidity at a sub-system level. In addition, discernible variations of both the magnitude and direction of weather's effect were found at the sub-system level. Developing a more geographically detailed understanding of the effect of weather on public transport services serves as a critical first step towards establishing a more weather-resilient public transport system. This new understanding has the potential to contribute to an evidence base that can be used to proactively adjust public transport services in response to changes in weather conditions across different parts of the network. Further research is needed to assess how transferable our findings are to other public transport and climatic contexts.

The article can be read here

Bus Bunching Explained Visually

 

Any bus rider knows what a problem bus bunching can be. (Anybody riding AC Transit's 51B to campus lives with this daily.) It's a popular research topic, with many articles and reports exploring the causes and solutions to prevent bunching.

ITS PhD student Lewis Lehe and designer Dennys Hess have developed visualization to explain why bus bunching happens. (You need to use Chrome.) Go try it out. CityLab and Metafilter are talking about it.  

Lehe has made many other visualizations explaining transportation phenomena like gridlock vs. bottlenecks and traffic waves. You can see more of his work on setosa.io

Accessibility and the Sharing Economy: Leap, Uber, Lyft and ADA requirements


Creative Commons licensed ( BY-NC-SA ) flickr photo shared by pix.plz

The disruption of traditional transportation by startups like Uber and Lyft has created waves and caused many cities and agencies to re-examine how they regulate taxis and the livery system. Now it looks like upstarts like Leap and Chariot, aiming to disrupt public transit, may be on the same course. 

It was reported today that last month a complaint was filed with the Department of Justice because Leap has failed to make its buses accessible to wheelchairs. This echoes similar concerns that has been expressed about Uber and Lyft. It is important to note that the Americans with Disabilities Act (ADA) does not require automobiles to be accessible, while other types of vehicles (vans and buses) must be accessible. 

Transit is crucial in providing accessible mobility options for people with disabilities, which is important to the quality of life. There has been much research focused on how to improve these transportation networks, including using taxis as a potential form of paratransit. TNCs like Uber and Lyft have improved accessible for some groups, it has been inconsistent. This review of Uber from the American Foundation for the Blind (AFB) points out the service works well with iOS, but that they Android app is not accessible. There is also the issue that riders with guide dogs might be refused a ride and "there appears to be no legal recourse that can be taken under the ADA at this time." The AFB has since filed a lawsuit against Uber and the DOJ now says Uber must comply with ADA. These sorts of regulatory growing pains seem to be a part of disruptive transportation companies maturity, which is why the complaint filed against Leap isn't very surprising. 

The Leap case also raises the existential question - what does it mean to be a transit service? Part of Leap's argument is that they do not provide transit, rather they connect riders with an operator. This is the same position Uber and Lyft have taken with regard to its relationship with riders and drivers, which also has a lawsuit in the courts. Leap and Chariot are basically modern jitneys that compliment existing services and jitneys are not exempt ADA requirements.

Making City-Scale Networks of Connected Vehicles Reality


creative commons licensed ( BY-NC-ND ) flickr photo shared by Roberto Maldeno

Last week's Friday Seminar featured João BarrosAssociate Professor at the University of Porto and CEO of Veniam talking about how he and his team turned public transit into smart city hot spots for Porto. After early attempts to use cellular technology for connected vehicles, which had major bottlenecks in the networks and was cost prohibitive, Barros explored the possibilities of using wi-fi technology to create a city wide mesh network. This builds upon some of Barros' earlier research that looked into the feasibility and impact of VANETs in urban environments

The key to Veniam's success on Porto has been the city's fibre-optic backbone to create wifi hotspots around the city, like bus stops. A combination of wifi and the IEEE 802.11p standard for wireless vehicle communication, and deployment in fleets such as many of the city's taxis and Metro de Porto's fleet, made the city wide mesh network possible. It also made it very cheap to offer free wifi on the entire bus fleet, which has pleased passengers

For the buses, the connectivity can be used for ticketing, navigation, infotainment, and vehicle diagnostics. This has also created a very rich, high definition data set of the fleet's operations which has informed service and route updates. 

The mesh network has also been very effective in tracking operations at Porto de Leixões. Early attempts to track vehicles with cellular technology were hindered by the lack of cell towers in the industrial area and interference from shipping containers. The wifi mesh network has made it possible to track port traffic to improve efficiency and safety. 

Barros hinted that the next wave of innovation could be in the field of wearables. His group had a project that tracked bus driver comfort and stress to better understand their behavior and how it depends on the built environment. 

Everybody loves bus bunching.

Corporation Atlanteans at Moreton Shore

Or more realistically, everybody loves to complain about bus bunching - when two or more buses (usually on the same line) should be evenly spaced out, but are right behind one another. Here around UC Berkeley AC Transit's 51b in the line most people complain about bunching (they're working on it!), but every transit systems has its own problem line(s). 

Earlier this week WBEZ's Curious City examines bus bunching in Chicago. They provide an easy to understand animation that demonstrates how minor service delays cascade to bus bunching. Bookmark it to share with your friends next time they lament about the topic. 

The topic is also beloved by transit researchers, particularly at ITS Berkeley. From systematic analysis of why bunching occurs to ways to solve the problem. And as always, you can find more research on bus bunching at TRID

A Brief History of GTFS

Time within each minute that Muni buses are typically reported at each location

Hang out around transportation geeks enough and you'll hear people throwing around the term GTFS. People throw it around on Twitter like crazy. It's an important part of the transit data landscape, so let's take a look at it. 

GTFS is also known as the General Transit Feed Specification. It was originally known as the Google Transit Feed Specification and was used to integrate transit into Google Maps, but the name was changed as more people began to use GTFS beyond the Google platform. GTFS allows agencies to easily publish their route data so that it can be used for trip planning, data visualization, and improved accessibility. For a good history of GTFS, read this chapter from Beyond Transparency

Portland's TriMet was one of the first agencies to really implement GTFS to much scuccess. And soon others like BART and MBTA followed suit. For a comprehensive list of agencies with GTFS feeds check out the GTFS Data Exchange. One of the more recent GTFS developments has been the launce of GTFS-realtime which, as the name implies, allows agencies to provide realtime information about transit services to users. 

A company spun out of ITS Berkeley research has extended GTFS to include operational data. VIA Analytics recently launched VTFS, which is based upon GTFS but also has AVL data. They also have visualization and tracking products, and they're all open source.  

 

Bikeshare as Public Transit

Nice Ride Minnesota

As bikeshare systems grow, mature, and become quite common, researchers are beginning to answer some fundamental questions about bikeshare. Are bikeshare cyclists fundamentally different from regular cyclists? What about riders wearing helmets? How does weather affect bikeshare trips? How do bikeshare users integrate with other modes?

What about bikeshare as public transit?

That's what TSRC researchers Elliot Martin and Susan Shaheen have asked in their forthcoming article, "Evaluating public transit modal shift dynamics in response to bikesharing: a tale of two U.S. cities" in Journal of Transport Geography. They conclude that:

The modal shift to and from public transit has shown an intriguing degree of variation within and across cities, meriting further exploration in this paper. The authors found, through mapping the modal shifts reported by members, that shifts away from public transit are most prominent in core urban environments with high population density. Shifts toward public transit in response to bikesharing appear most prevalent in lower density regions on the urban periphery.

The full article can be found here. Or your can read an overview from CityLab

Transport Infrastructure and the World Cup

III Congresso SIBRT

Last week the 2014 FIFA World Cup kicked off in Brazil. Mega sporting events, like the World Cup and the Olympics, often require mega infrastructure projects for the hosts. For this World Cup, preparations include building five new stadiums, including the much talked about Arena Amazônia in Manaus which almost wasn't ready for the first match, and several transport projects. Airports were considered a headache early in planning, and lots of money and time has been invested in airport upgrades for an already overtaxed civil air system. On the other side, several planned public transport projects, such as monorails in Sao Paulo and Manaus, were cancelled because they could not be delivered in time for the tournament. One of the few public transport projects that succeeded was Belo Horizonte's MOVE BRT, which launched in March 2014. 

Some researchers have called these projects a "missed opportunity" to improve urban mobility in Brazil. Others have focused on how these projects could have reduced transport greenhouse gas emissions if only they were built. (Some of them were quite sustainable.)

For a good roundup of World Cup transport projects winner and losers, NextCity provides a good overview

Friday Seminar: Improving Bus Service with a Scalable Dynamic Holding Control

Commuter Warning

This week's Friday Seminar features UC Berkeley Ph.D. candidate Juan Argote presenting his research on control methods for transit services in, "Improving Bus Service with a Scalable Dynamic Holding Control":

Service unreliability is widely recognized as one of the main deterrents for travelers to use buses as their mode of transportation. Bus systems are exposed to an adverse feedback loop that generates a tendency for them to fall out of sync. This tendency can be counteracted by the application of control strategies that regulate the motion of the buses. This is well known among transit operators and some research has been devoted to address the issue. However, existing methods that are simple enough to be scalable can only handle headway-based operations of a single line.

This research proposes a scalable control method that applies dynamic holding based on real-time conditions and that allows buses to stay on schedule. A formulation that generalizes dynamic holding control strategies is developed for isolated bus lines. Stability conditions are derived and a quasi-optimal control that requires minimal data is also presented. The performance of this control is validated through simulation. The control is then extended to corridors where multiple bus lines overlap. A real-world case study in San Sebastián, where a system of coordinated on-board devices was deployed, is used to validate the control performance in this type of scenario. Finally, the resilience of the control is assessed considering multiple potential adversities.

The seminar takes place on Friday, April 25 in 534 Davis from 4-5 PM. Cookie Hour will be in the library at 3:30. 

 

New Article: Macroscopic Fundamental Diagram and Public Transport

Changing Course in Urban Transport

A brand new article in Transportation Research Part C: Emerging Technologies examines a macroscopic fundamental diagram (MFD) and how it is applied to bi-modal urban networks. "A three-dimensional macroscopic fundamental diagram for mixed bi-modal urban networks," by (ITS alum) Nikolas Geroliminis, Nan Zheng,and Konstantinos Ampountolas investigates existence of a three-dimensional vehicle-flow MFD for bi-modal network.

Recent research has studied the existence and the properties of a macroscopic fundamental diagram (MFD) for large urban networks. The MFD should not be universally expected as high scatter or hysteresis might appear for some type of networks, like heterogeneous networks or freeways. In this paper, we investigate if aggregated relationships can describe the performance of urban bi-modal networks with buses and cars sharing the same road infrastructure and identify how this performance is influenced by the interactions between modes and the effect of bus stops. Based on simulation data, we develop a three-dimensional vehicle MFD (3D-vMFD) relating the accumulation of cars and buses, and the total circulating vehicle flow in the network. This relation experiences low scatter and can be approximated by an exponential-family function. We also propose a parsimonious model to estimate a three-dimensional passenger MFD (3D-pMFD), which provides a different perspective of the flow characteristics in bi-modal networks, by considering that buses carry more passengers. We also show that a constant Bus–Car Unit (BCU) equivalent value cannot describe the influence of buses in the system as congestion develops. We then integrate a partitioning algorithm to cluster the network into a small number of regions with similar mode composition and level of congestion. Our results show that partitioning unveils important traffic properties of flow heterogeneity in the studied network. Interactions between buses and cars are different in the partitioned regions due to higher density of buses. Building on these results, various traffic management strategies in bi-modal multi-region urban networks can then be integrated, such as redistribution of urban space among different modes, perimeter signal control with preferential treatment of buses and bus priority.

The full paper can be found here.

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