Footage from inside Brisbane bus after Toyota launched into it

Incredible video shows the bus driver helping the woman from the Toyota Yaris that ended up lodged in a bus in Brisbane's south on July 29.

smh.com.au

Why Battery-Swapping EVs Still Haven't Made Highway Fast Charging Obsolete - Jalopnik

jalopnik.com

Transportist: August 2026

Most of you received the TransportLab: July 2026 post, so I gave you a pause. Also traveling to Beijing, Chengdu, and Hangzhou China last month. Welcome to the latest issue of The Transportist, especially to our new readers. As always you can follow me on Mastodon, BlueSky, or RSS. You might have noticed the site logo changed. Been meaning to for a while, but prompted when I received a nasty-gram from Transport for London, who worried, I suppose, you (well not you, but someone) might be confused that this here newsletter was a transit stop and not a newsletter, so they must protect their trademark, despite the roundel being a universal symbol, me being in Australia, and the newsletter being hosted in the US. Roundels are an old visual form. They appear in heraldry, flags, aviation, military insignia, civic marks, and commercial design. The form long predates London Transport, and is widely used outside London. Feel free to send in pictures of people abusing the roundel for non-authorised purposes, and I will share them over time to help out the lawyers at TfL (or inundate them with too many signs to chase down).Wynyard Station, not on the London Underground. No one is confused.Sexy Dynamite logo in Japan. No one is confused or stops in looking for trains to King’s Cross. (Well, maybe they do, I don’t know). Pointers Transit & Cities * The Transit Abundance Playbook — Institute for Progress * How Madrid Built the World’s Best Metro — YouTube Automation * China Resumes Issuing Robotaxi Licenses After Months-Long Freeze — Bloomberg * We took a self-driving car on the road for 100 days to see how it handled itself – these are the mistakes it kept making — Zuduo Zheng, UQ News / The Conversation * San Francisco’s fireworks show ends in hours of gridlock involving Waymo cars — NBC Bay Area Roads & Behaviour * Supercars, viral clout and the Sydney suburbs left sleepless — Sydney Morning Herald (hooning) * This Simple White Line Is America’s Greatest Unsung Innovation — Ben Cohen, WSJ * Former Italian motorway boss among 32 convicted over Genoa bridge tragedy - Reuters Policy * Californians sour on Newsom’s push to ban gas-powered cars— George Skelton, Los Angeles Times (Newsom and EVs) * Digital travel declaration to replace paper incoming passenger card — The Guardian Elsewhere * There’s a Global Network of Fungi Under Your Feet. This Is the First Complete Map — Wired Supply Chains * The U.S. is using an Iranian smuggling tactic to sneak oil out of the Gulf - Animal Transport * Central Park Horse Carriage Death ends industry Your regular reminder that cars are weapons * Militant attack on Pakistan Rangers HQ in Karachi sparks gunfire * Attack on Berlin Pride Parade Posts Publications Press Charis Chang on SBS posted High-speed rail is a decades-old Australian dream. One factor could finally make it real 28 June 2026 The Quote But professor David Levinson, civil engineer and transportation analyst at the University of Sydney, is sceptical about the project and says, if delivered, it would likely feature the longest high-speed tunnel in the world. “As shown by Snowy II and the M6 Motorway in Arncliffe, things can go wrong with tunnelling, driving up costs,” he tells SBS News. In engineering we talk about quality, speed, and cost — and generally you can only get two out of three. “They are proposing to open this in ten years, and make mention of using new ‘green’ concrete technology, which obviously brings with it risks, as does any new technology.” The Full set of questions I answered: * Despite many proposals for high-speed rail in Australia, none have got off the ground, why is this? They have always been considered too expensive for the benefit provided. Even if they are worthwhile for society, finding the financing for them has always been difficult. One imagines some kind of public-private partnership, like some Australia states do with TransUrban, where there is a contract paying the provider revenue and an availability payment in exchange for the up front investment (usually from superannuation funds) over a fixed term. Whether this maximises benefits for Australia is unclear. And it is unclear why everyone in Australia should pay for a line in a single corridor serving Newcastle and Central Coast, while other corridors remain underserved. * Do you think the current proposal is any different from previous ones? The released documents show a Benefit/Cost ratio under 1.0 under all but the most optimistic assumptions. This proposal has also made more optimistic assumptions about land use changes and “Wider Economic Benefits” about which Treasury officials are generally skeptical. I refer you to page 9 of the IA Business Case Evaluation Report Also see the Business Case (section 7.6) It is different from previous proposals in that it serves even fewer people. * The Newcastle and Sydney section is considered the most challenging to deliver – why is this? What are the engineering challenges? As proposed by the Commonwealth it includes an extensive amount of tunnelling, probably the longest high-speed rail tunnel in the world. As shown by Snowy II and the M6 Motorway in Arncliffe, things can go wrong with tunneling, driving up costs. In engineering we talk about Quality, Speed, and Cost, and generally you can only get two out of three, Prioritising Speed and Cost will lost Quality, prioritising Cost and Quality will lose Speed, etc. They are proposing to open this in 10 years, and make mention of using new “green” concrete technology, which obviously brings with it risks as does any new technology. * I’ve been told that keeping the travel time to 1 hour would be ideal so that Newcastle can be within reasonable commuting time to Sydney, is this feasible? If they build it, 1 hour point-to-point (i.e. station-to-station) is feasible. Whether this is “a reasonable commuting time to Sydney” is an open question. Note it assumes the commuter lives on top of the station at Newcastle, and works on top of the station at Central. I can take 10 minutes just to get from a train to the exits at Central Station, so access and egress costs need to be considered. If someone is transferring trains or to buses at Central, that is also added time to the final destination. Most people in Sydney don’t actually work at Central station, which is the southern end of the CBD. But all of this assumes cities will retain their same importance if the future that they have today, despite Work-from-Home, AI, and all of the technological changes we cannot foresee. It also assumes a “Big Australia” that growth via migration will keep coming. I don’t believe the party currently polling number one agrees with that forecast. In the absence of migration, Australia would be losing population. * Do you think this project will actually happen? “Rationality” is not the word most associated with government. I also asked a local LLM (Ollama) which has access to my corpus. It answered as below: * High-speed rail projects in Australia face challenges due to fiscal risks from cost overruns and uncertain operating-cost recovery, which create unacceptable risks for states * The Newcastle and Sydney section is particularly challenging due to complex geography, existing infrastructure, and the need for high-speed corridors that balance speed with safety and environmental constraints * Keeping travel time to 1 hour between Newcastle and Sydney is feasible in theory, but it requires significant investment in infrastructure and operational efficiency to meet such a tight timeframe * The current proposal is not fundamentally different from previous ones, as it still faces similar fiscal, technical, and political hurdles that have historically stalled high-speed rail in Australia * The project’s success depends on overcoming these challenges, but without substantial funding and political will, it may not materialize as planned TransportLab visit China’s leading toll road operator to strengthen research collaboration At the invitation of Zhejiang Communications Investment Group (CICO), Professor David Levinson and Professor Chen Cai from TransportLab visited the company’s headquarters in Hangzhou, China, on 17–18 Jun. A Fortune 500 company, CICO is the largest builder and operator of tolled motorways in China. During the visit, the TransportLab team held a series of meetings and dialogues with CICO executives to explore opportunities for future research and education partnerships. The centrepiece of the proposed collaboration is a CICO-funded Industry PhD Program at the School of Civil Engineering, aimed at advancing research in intelligent transport systems. The visit provided a valuable opportunity to showcase the University of Sydney’s expertise in transport research, while offering first-hand insight into China’s transport innovations, technology strategies, and advanced manufacturing capabilities. It further strengthened relationships with academic and industry partners and opened new avenues for international collaboration. Random Videos * Nice use of transport examples to explain hash tables, featuring the work of Andrew Krapivin. The video probably has an AI voice, but the explainer is good.

dlvr.it

Transportist: August 2026

Most of you received the TransportLab: July 2026 post, so I gave you a pause. Also traveling to Beijing, Chengdu, and Hangzhou China last month. Welcome to the latest issue of The Transportist, especially to our new readers. As always you can follow me on Mastodon, BlueSky, or RSS. You might have noticed the site logo changed.

transportist.org

Transportist: August 2026

Most of you received the TransportLab: July 2026 post, so I gave you a pause. Also traveling to Beijing, Chengdu, and Hangzhou China last month. Welcome to the latest issue of The Transportist, especially to our new readers. As always you can follow me on Mastodon, BlueSky, or RSS. You might have noticed the site logo changed. Been meaning to for a while, but prompted when I received a nasty-gram from Transport for London, who worried, I suppose, you (well not you, but someone) might be confused that this here newsletter was a transit stop and not a newsletter, so they must protect their trademark, despite the roundel being a universal symbol, me being in Australia, and the newsletter being hosted in the US. Roundels are an old visual form. They appear in heraldry, flags, aviation, military insignia, civic marks, and commercial design. The form long predates London Transport, and is widely used outside London. Feel free to send in pictures of people abusing the roundel for non-authorised purposes, and I will share them over time to help out the lawyers at TfL (or inundate them with too many signs to chase down).Wynyard Station, not on the London Underground. No one is confused.Sexy Dynamite logo in Japan. No one is confused or stops in looking for trains to King’s Cross. (Well, maybe they do, I don’t know). Pointers Transit & Cities * The Transit Abundance Playbook — Institute for Progress * How Madrid Built the World’s Best Metro — YouTube Automation * China Resumes Issuing Robotaxi Licenses After Months-Long Freeze — Bloomberg * We took a self-driving car on the road for 100 days to see how it handled itself – these are the mistakes it kept making — Zuduo Zheng, UQ News / The Conversation * San Francisco’s fireworks show ends in hours of gridlock involving Waymo cars — NBC Bay Area Roads & Behaviour * Supercars, viral clout and the Sydney suburbs left sleepless — Sydney Morning Herald (hooning) * This Simple White Line Is America’s Greatest Unsung Innovation — Ben Cohen, WSJ * Former Italian motorway boss among 32 convicted over Genoa bridge tragedy - Reuters Policy * Californians sour on Newsom’s push to ban gas-powered cars— George Skelton, Los Angeles Times (Newsom and EVs) * Digital travel declaration to replace paper incoming passenger card — The Guardian Elsewhere * There’s a Global Network of Fungi Under Your Feet. This Is the First Complete Map — Wired Supply Chains * The U.S. is using an Iranian smuggling tactic to sneak oil out of the Gulf - Animal Transport * Central Park Horse Carriage Death ends industry Your regular reminder that cars are weapons * Militant attack on Pakistan Rangers HQ in Karachi sparks gunfire * Attack on Berlin Pride Parade Posts Publications Press Charis Chang on SBS posted High-speed rail is a decades-old Australian dream. One factor could finally make it real 28 June 2026 The Quote But professor David Levinson, civil engineer and transportation analyst at the University of Sydney, is sceptical about the project and says, if delivered, it would likely feature the longest high-speed tunnel in the world. “As shown by Snowy II and the M6 Motorway in Arncliffe, things can go wrong with tunnelling, driving up costs,” he tells SBS News. In engineering we talk about quality, speed, and cost — and generally you can only get two out of three. “They are proposing to open this in ten years, and make mention of using new ‘green’ concrete technology, which obviously brings with it risks, as does any new technology.” The Full set of questions I answered: * Despite many proposals for high-speed rail in Australia, none have got off the ground, why is this? They have always been considered too expensive for the benefit provided. Even if they are worthwhile for society, finding the financing for them has always been difficult. One imagines some kind of public-private partnership, like some Australia states do with TransUrban, where there is a contract paying the provider revenue and an availability payment in exchange for the up front investment (usually from superannuation funds) over a fixed term. Whether this maximises benefits for Australia is unclear. And it is unclear why everyone in Australia should pay for a line in a single corridor serving Newcastle and Central Coast, while other corridors remain underserved. * Do you think the current proposal is any different from previous ones? The released documents show a Benefit/Cost ratio under 1.0 under all but the most optimistic assumptions. This proposal has also made more optimistic assumptions about land use changes and “Wider Economic Benefits” about which Treasury officials are generally skeptical. I refer you to page 9 of the IA Business Case Evaluation Report Also see the Business Case (section 7.6) It is different from previous proposals in that it serves even fewer people. * The Newcastle and Sydney section is considered the most challenging to deliver – why is this? What are the engineering challenges? As proposed by the Commonwealth it includes an extensive amount of tunnelling, probably the longest high-speed rail tunnel in the world. As shown by Snowy II and the M6 Motorway in Arncliffe, things can go wrong with tunneling, driving up costs. In engineering we talk about Quality, Speed, and Cost, and generally you can only get two out of three, Prioritising Speed and Cost will lost Quality, prioritising Cost and Quality will lose Speed, etc. They are proposing to open this in 10 years, and make mention of using new “green” concrete technology, which obviously brings with it risks as does any new technology. * I’ve been told that keeping the travel time to 1 hour would be ideal so that Newcastle can be within reasonable commuting time to Sydney, is this feasible? If they build it, 1 hour point-to-point (i.e. station-to-station) is feasible. Whether this is “a reasonable commuting time to Sydney” is an open question. Note it assumes the commuter lives on top of the station at Newcastle, and works on top of the station at Central. I can take 10 minutes just to get from a train to the exits at Central Station, so access and egress costs need to be considered. If someone is transferring trains or to buses at Central, that is also added time to the final destination. Most people in Sydney don’t actually work at Central station, which is the southern end of the CBD. But all of this assumes cities will retain their same importance if the future that they have today, despite Work-from-Home, AI, and all of the technological changes we cannot foresee. It also assumes a “Big Australia” that growth via migration will keep coming. I don’t believe the party currently polling number one agrees with that forecast. In the absence of migration, Australia would be losing population. * Do you think this project will actually happen? “Rationality” is not the word most associated with government. I also asked a local LLM (Ollama) which has access to my corpus. It answered as below: * High-speed rail projects in Australia face challenges due to fiscal risks from cost overruns and uncertain operating-cost recovery, which create unacceptable risks for states * The Newcastle and Sydney section is particularly challenging due to complex geography, existing infrastructure, and the need for high-speed corridors that balance speed with safety and environmental constraints * Keeping travel time to 1 hour between Newcastle and Sydney is feasible in theory, but it requires significant investment in infrastructure and operational efficiency to meet such a tight timeframe * The current proposal is not fundamentally different from previous ones, as it still faces similar fiscal, technical, and political hurdles that have historically stalled high-speed rail in Australia * The project’s success depends on overcoming these challenges, but without substantial funding and political will, it may not materialize as planned TransportLab visit China’s leading toll road operator to strengthen research collaboration At the invitation of Zhejiang Communications Investment Group (CICO), Professor David Levinson and Professor Chen Cai from TransportLab visited the company’s headquarters in Hangzhou, China, on 17–18 Jun. A Fortune 500 company, CICO is the largest builder and operator of tolled motorways in China. During the visit, the TransportLab team held a series of meetings and dialogues with CICO executives to explore opportunities for future research and education partnerships. The centrepiece of the proposed collaboration is a CICO-funded Industry PhD Program at the School of Civil Engineering, aimed at advancing research in intelligent transport systems. The visit provided a valuable opportunity to showcase the University of Sydney’s expertise in transport research, while offering first-hand insight into China’s transport innovations, technology strategies, and advanced manufacturing capabilities. It further strengthened relationships with academic and industry partners and opened new avenues for international collaboration. Random Videos * Nice use of transport examples to explain hash tables, featuring the work of Andrew Krapivin. The video probably has an AI voice, but the explainer is good.

dlvr.it

Van slams into people gathered for Berlin's LGBTQ+ event, killing 1 and injuring at least 15

A van that drove into a crowd during Berlin's LGBTQ+ event has killed one person and injured at least 15.

apnews.com

Job: Postdoctoral Research Associate in Applied Quantum Computing Research

Full time fixed term for 12 months at Camperdown Campus Opportunity to join a pioneering research program focused on digital innovation, quantum-enhanced modelling, and resilient infrastructure systems Base Salary Level A, $117,936 - $125,896 + 17% superannuation Working under the supervision of Professor David Levinson, Neda Madi, PhD and Chen Cai the successful candidate will contribute to the development of hybrid quantum–classical modelling approaches that support improved analysis, simulation, optimisation, and decision making under uncertainty. The role will suit a researcher with strong technical capability in quantum computing, data-driven modelling, infrastructure systems, computational optimisation, simulation, probabilistic methods, or related areas. Your key responsibilities will be to: * conduct high-quality research in quantum-enabled computational approaches for digital twins and complex system simulations * develop, implement, test, and benchmark computational models, algorithms, data pipelines, and research software prototypes * contribute to optimisation, simulation, sampling, or uncertainty-modelling approaches for complex systems * analyse infrastructure, spatial, temporal, networked, or urban systems data contribute to the preparation and submission of journal articles, conference papers, technical reports, and research outputs * collaborate with interdisciplinary scholars across engineering, design, planning, computing, and related research domains * contribute to stakeholder engagement activities, including workshops, research presentations, and partner-facing materials * assist with the development of competitive grant applications and future external funding opportunities. Work Rights You must have unrestricted work rights in Australia for the duration of this employment to apply. Visa sponsorship is not available for this appointment. Link: https://usyd.wd105.myworkdayjobs.com/en-GB/USYD_EXTERNAL_CAREER_SITE/job/Darlington-Campus/Postdoctoral-Research-Associate-in-Applied-Quantum-Computing-Research_0153792-2

dlvr.it

A simulation-based policy evaluation of healthcare access using heterogeneous emergency medical services vehicles and incidents

Recently published: * Song, C., Levinson, D. and Moylan, E. (2026) A simulation-based policy evaluation of healthcare access using heterogeneous emergency medical services vehicles and incidents. Transport Policy, Volume 187, October 2026, 104293. [doi] Efficient dispatch policies are critical for ensuring equitable and effective emergency medical services (EMS). While vehicle specialisation offers tangible clinical benefits, integrating vehicle types into dispatch policy presents significant challenges. This study employs an agent-based simulation framework to evaluate the effects of alternative dispatch policies under varying proportions of specialised ambulances. Results indicate that allowing specialised vehicles to respond to a broader range of high-priority incidents enhances overall survival rates. However, the benefits of specialisation depend on how these vehicles are deployed within the system. When the supply of specialised vehicles exceeds demand, restrictive policies lead to longer response times and worsened outcomes for non-prioritised cases. In particular, restricting specialised vehicles to a narrow set of incidents can reduce overall system efficiency by limiting dispatch flexibility and increasing waiting times for other patients. Moderately flexible dispatch policies provide balance between outcome efficiency and response equity. These findings suggest that both the proportion of specialised vehicles and their dispatch eligibility should reflect the underlying mix of incidents in order to avoid over-constraining the system. Spatial analysis shows that survival and response disparities are more pronounced in peripheral areas. These findings underscore the need to align dispatch policy and fleet composition with incident typology and spatial demand, offering actionable insights for EMS policy and resource planning. Keywords: Dispatching policy, Emergency medical services, Agent-based simulation, Vehicle classes, Incident types, PriorityFig. 15. Spatial distributions of response time in relation to different policies. The maps illustrate response times from simulations involving 4 special vehicles and 80 incidents, including 20% special incidents - of incidents. The red colors depict the average response time of all incidents in the regions; lighter colors indicate shorter response times, while grey indicates areas with no residents. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

dlvr.it

Water Conservation | Coachella Valley Water District - Official Website

Making every drop count is more than the Coachella Valley Water District slogan, it’s a way of life in the desert!

cvwd.org

Job: Postdoctoral Research Associate in Applied Quantum Computing Research

Full time fixed term for 12 months at Camperdown Campus Opportunity to join a pioneering research program focused on digital innovation, quantum-enhanced modelling, and resilient infrastructure systemsBase Salary Level A, $117,936 - $125,896 + 17% superannuation Working under the supervision of Professor David Levinson, Neda Madi, PhD and Chen Cai the successful candidate will contribute to the development of hybrid quantum–classical modelling approaches that support improved analysis, simulation, optimisation, and decision making under uncertainty.

transportist.org

Job: Postdoctoral Research Associate in Applied Quantum Computing Research

Full time fixed term for 12 months at Camperdown Campus Opportunity to join a pioneering research program focused on digital innovation, quantum-enhanced modelling, and resilient infrastructure systems Base Salary Level A, $117,936 - $125,896 + 17% superannuation Working under the supervision of Professor David Levinson, Neda Madi, PhD and Chen Cai the successful candidate will contribute to the development of hybrid quantum–classical modelling approaches that support improved analysis, simulation, optimisation, and decision making under uncertainty. The role will suit a researcher with strong technical capability in quantum computing, data-driven modelling, infrastructure systems, computational optimisation, simulation, probabilistic methods, or related areas. Your key responsibilities will be to: * conduct high-quality research in quantum-enabled computational approaches for digital twins and complex system simulations * develop, implement, test, and benchmark computational models, algorithms, data pipelines, and research software prototypes * contribute to optimisation, simulation, sampling, or uncertainty-modelling approaches for complex systems * analyse infrastructure, spatial, temporal, networked, or urban systems data contribute to the preparation and submission of journal articles, conference papers, technical reports, and research outputs * collaborate with interdisciplinary scholars across engineering, design, planning, computing, and related research domains * contribute to stakeholder engagement activities, including workshops, research presentations, and partner-facing materials * assist with the development of competitive grant applications and future external funding opportunities. Work Rights You must have unrestricted work rights in Australia for the duration of this employment to apply. Visa sponsorship is not available for this appointment. Link: https://usyd.wd105.myworkdayjobs.com/en-GB/USYD_EXTERNAL_CAREER_SITE/job/Darlington-Campus/Postdoctoral-Research-Associate-in-Applied-Quantum-Computing-Research_0153792-2

dlvr.it

Elderly US woman shocked to receive racy new car licence plate

The Florida retiree says the plate has caused quite a stir among her local community.

bbc.com

A simulation-based policy evaluation of healthcare access using heterogeneous emergency medical services vehicles and incidents

Recently published: Song, C., Levinson, D. and Moylan, E. (2026) A simulation-based policy evaluation of healthcare access using heterogeneous emergency medical services vehicles and incidents. Transport Policy, Volume 187, October 2026, 104293. Efficient dispatch policies are critical for ensuring equitable and effective emergency medical services (EMS). While vehicle specialisation offers tangible clinical benefits, integrating vehicle types into dispatch policy presents significant challenges.

transportist.org

A simulation-based policy evaluation of healthcare access using heterogeneous emergency medical services vehicles and incidents

Recently published: * Song, C., Levinson, D. and Moylan, E. (2026) A simulation-based policy evaluation of healthcare access using heterogeneous emergency medical services vehicles and incidents. Transport Policy, Volume 187, October 2026, 104293. [doi] Efficient dispatch policies are critical for ensuring equitable and effective emergency medical services (EMS). While vehicle specialisation offers tangible clinical benefits, integrating vehicle types into dispatch policy presents significant challenges. This study employs an agent-based simulation framework to evaluate the effects of alternative dispatch policies under varying proportions of specialised ambulances. Results indicate that allowing specialised vehicles to respond to a broader range of high-priority incidents enhances overall survival rates. However, the benefits of specialisation depend on how these vehicles are deployed within the system. When the supply of specialised vehicles exceeds demand, restrictive policies lead to longer response times and worsened outcomes for non-prioritised cases. In particular, restricting specialised vehicles to a narrow set of incidents can reduce overall system efficiency by limiting dispatch flexibility and increasing waiting times for other patients. Moderately flexible dispatch policies provide balance between outcome efficiency and response equity. These findings suggest that both the proportion of specialised vehicles and their dispatch eligibility should reflect the underlying mix of incidents in order to avoid over-constraining the system. Spatial analysis shows that survival and response disparities are more pronounced in peripheral areas. These findings underscore the need to align dispatch policy and fleet composition with incident typology and spatial demand, offering actionable insights for EMS policy and resource planning. Keywords: Dispatching policy, Emergency medical services, Agent-based simulation, Vehicle classes, Incident types, PriorityFig. 15. Spatial distributions of response time in relation to different policies. The maps illustrate response times from simulations involving 4 special vehicles and 80 incidents, including 20% special incidents - of incidents. The red colors depict the average response time of all incidents in the regions; lighter colors indicate shorter response times, while grey indicates areas with no residents. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

dlvr.it

A stochastic queueing model for travel time reliability with spatial density heterogeneity

Recently published: * Gao, Y. and Levinson, D. (2026) A stochastic queueing model for travel time reliability with spatial density heterogeneity. Transportation Research Part B, Volume 211, September 2026, 103544. [doi] This paper constructs a theoretical model connecting day-to-day travel time reliability (TTR) and vehicle density, testing it on freeway stretches in Minneapolis - St. Paul and San Diego. We establish the presence of a counter-clockwise hysteresis loop between average vehicle density and experienced travel time standard deviation. We also observe that vehicle density heterogeneity exerts a more profound effect on TTR during moderate congestion. We find that a timehomogeneous Poisson process accurately characterizes the vehicle arrival process on segments of freeway stretches, both with and without on-ramps, during the morning peak period. The travel times for these segments align well with an exponential distribution. Through an analysis of the travel time correlations among different segments of the freeway stretch, we find that this correlation is higher during congestion offset periods, resulting in more severe travel time fluctuations due to increased density heterogeneity. Using the M/M/1 queueing model, we derive a model encapsulating the variance of experienced travel time, average vehicle density, and density heterogeneity for freeway stretches consisting of multiple segments. We use the `birth-death process’ to model the relationship between average vehicle density and density heterogeneity. By integrating these two models, we derive a novel model that accurately approximates freeway stretch TTR based on average vehicle density and traffic flow. We apply our models to TTR changes on the two selected freeway stretches to validate across different time periods and select two subnetworks, each containing three additional freeway stretches, to validate across spatial dimensions. The results from these experiments corroborate the robustness and generality of our model across both temporal and spatial contexts. Keywords: Travel time reliability, Density heterogeneity, Queueing theoryFig. 2. Relationship between average vehicle density and experienced travel time mean and STD (a) and average vehicle density and vehicle density heterogeneity (b) for selected freeway stretches.

dlvr.it

Solving climate variability

March 32, 2014

transportist.net

A stochastic queueing model for travel time reliability with spatial density heterogeneity

Recently published: Gao, Y. and Levinson, D. (2026) A stochastic queueing model for travel time reliability with spatial density heterogeneity. Transportation Research Part B, Volume 211, September 2026, 103544. This paper constructs a theoretical model connecting day-to-day travel time reliability (TTR) and vehicle density, testing it on freeway stretches in Minneapolis - St. Paul and San Diego. We establish the presence of a counter-clockwise hysteresis loop between average vehicle density and experienced travel time standard deviation.

transportist.org

A stochastic queueing model for travel time reliability with spatial density heterogeneity

Recently published: * Gao, Y. and Levinson, D. (2026) A stochastic queueing model for travel time reliability with spatial density heterogeneity. Transportation Research Part B, Volume 211, September 2026, 103544. [doi] This paper constructs a theoretical model connecting day-to-day travel time reliability (TTR) and vehicle density, testing it on freeway stretches in Minneapolis - St. Paul and San Diego. We establish the presence of a counter-clockwise hysteresis loop between average vehicle density and experienced travel time standard deviation. We also observe that vehicle density heterogeneity exerts a more profound effect on TTR during moderate congestion. We find that a timehomogeneous Poisson process accurately characterizes the vehicle arrival process on segments of freeway stretches, both with and without on-ramps, during the morning peak period. The travel times for these segments align well with an exponential distribution. Through an analysis of the travel time correlations among different segments of the freeway stretch, we find that this correlation is higher during congestion offset periods, resulting in more severe travel time fluctuations due to increased density heterogeneity. Using the M/M/1 queueing model, we derive a model encapsulating the variance of experienced travel time, average vehicle density, and density heterogeneity for freeway stretches consisting of multiple segments. We use the `birth-death process’ to model the relationship between average vehicle density and density heterogeneity. By integrating these two models, we derive a novel model that accurately approximates freeway stretch TTR based on average vehicle density and traffic flow. We apply our models to TTR changes on the two selected freeway stretches to validate across different time periods and select two subnetworks, each containing three additional freeway stretches, to validate across spatial dimensions. The results from these experiments corroborate the robustness and generality of our model across both temporal and spatial contexts. Keywords: Travel time reliability, Density heterogeneity, Queueing theoryFig. 2. Relationship between average vehicle density and experienced travel time mean and STD (a) and average vehicle density and vehicle density heterogeneity (b) for selected freeway stretches.

dlvr.it

Australian scientist ignites war over the world's longest lives

The Blue Zones grew into a global wellness brand aided by stories of legendary old age. But a bitter feud over the science has shaken their foundations.

abc.net.au

MTA bus crash, string of collisions injure over 30 in Baltimore County

Baltimore County fire crews responded after a bus crashed into a building Wednesday in Pikesville, leaving 33 people injured.

thebanner.com