Freight

A container ship rammed into the Francis Scott Key Bridge in Baltimore around 1:30 a.m. on March 26, 2024, causing a portion of the bridge to collapse into Baltimore Harbor. Officials called the event a mass casualty and were searching for people in the waters of the busy port. This event occurred less than a year after a portion of Interstate 95 collapsed in north Philadelphia during a truck fire. That disaster was initially expected to snarl traffic for months, but a temporary six-lane roadway was constructed in 12 days to serve motorists while a permanent overpass was rebuilt. U.S. cities often face similar challenges when routine wear and tear, natural disasters or major accidents damage roads and bridges. Transportation engineer Lee D. Han explains how planners, transit agencies and city governments anticipate and manage these disruptions. How do agencies plan for disruptions like this? Planning is a central mission for state and metropolitan transportation agencies. T...

As part of its effort to reduce air pollution and cut greenhouse gas emissions that contribute to climate change, California is pursuing aggressive policies to promote clean trucks. The state already requires that by 2035, all new cars and other light-duty vehicles sold in the state must be zero emission. Its powerful Air Resources Board has adopted rules requiring that most trucks be zero emission by 2035, and is now proposing that all trucks sold by 2040 must be zero emission. The Conversation asked a panel of transportation experts from the University of California, Davis what’s involved in such a rapid transition. 1. Why is California targeting medium- and heavy-duty trucks? Although diesel engines are valuable for moving heavy loads, they also are major polluters. Diesel trucks account for one-fourth of greenhouse gas emissions and about half of conventional air pollution from transportation in U.S. cities. Pollutants in diesel exhaust include nitrogen oxides, fine...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com. How many Amazon packages get delivered each year? – Aya K., age 9, Illinois It’s incredibly convenient to buy something online, right from your computer or phone. Whether it’s a high-end telescope or a resupply of toothpaste, the goods appear right at your doorstep. This kind of shopping is called “e-commerce” and it’s becoming more popular each year. In the U.S., it has grown from a mere 7% of retail purchases in 2012 to 19.6% of retail and US$791.7 billion in sales in 2020. Amazon’s growing reach For Amazon, the biggest player in e-commerce, this means delivering lots of packages. In 2021 the company shipped an estimated 7.7 billion packages globally, based on its nearly $470 billion in sal...