If mathematicians addressed traffic problems

How would mathematicians solve traffic? Here are the suggestions from a 2020 book:

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All drivers need to be on the same navigation system. Cars can only be efficiently rerouted if instructions come from one center hub. One navigation system rerouting some drivers does not solve traffic jams.

Parking bans. Many urban roads are too narrow and cannot be physically widened. Traffic-flow models can indicate where parking spots should be turned into lanes.

Green lanes. For cities that want to increase electric car use, special lanes should be created for electric cars, providing an incentive for their use.

Digital twins. Traffic demands and available infrastructure can only be balanced with digital modeling that creates an entire “twin” of existing roadways. The software will be “an extremely useful thought tool in the hands of transport engineers.”

I have not read the book and this description is not long but it seems to depend on both understanding current and possible traffic flows through modeling. Often, Americans typically get more lanes added to roads – which then tend to fill up because there is more capacity and/or populations continue to grow.

I wonder how modeling would fit with other values underlying road and traffic decisions. A few examples:

  1. It might be better to have a centralized traffic and navigation hub. Is this technically feasible, would all car makers want to participate, and would there be privacy concerns?
  2. The politics of providing special lanes, whether for electric cars or high occupancy vehicles or bicycles, can get interesting. Americans often think the roadway should be for all users as opposed to particular users.
  3. The road system we have is the result of not just prioritizing efficiency but a whole host of actors and forces that includes privileging single-family homes (and generally keeping them away from busy roads) and highways in and out of major cities.

The foresight of old railway viaducts

In regions like Chicagoland where there are numerous railroad lines and at-grade railroad crossings, old viaducts exhibit a measure of foresight that benefits today’s residents:

Google Street View image of Vollmer Road viaduct

That factory still operates as Chicago Heights Steel, and the cobblestone portion of Main Street is mostly a driveway leading to it. But just past the factory is a secret passageway of sorts, an ancient viaduct just wide enough to allow one vehicle to pass under the old Elgin, Joliet & Eastern railroad tracks…

There are areas, though, where there are no ways around it, and if you get stopped, you just have to abide. I’ve lived in those areas, but I don’t anymore. The main train line by me is above grade and it’s great. The old Illinois Central tracks, which include what’s now known as the Metra Electric District commuter line, traverse the area atop a big berm as unobstructed motorists cruise underneath through a series of viaducts from Sauk Trail all the way into the heart of Chicago.

According to Metra, the grade separation was a direct result of Chicago hosting the 1893 World’s Columbian Exhibition — city leaders didn’t want messy train deaths to tarnish the event’s image. In the years after those initial express trains from downtown to Jackson Park for the World’s Fair, commuter trains made their way to the suburbs, with Flossmoor getting service in 1900 and Matteson by 1912. The raised platforms, tracks and viaducts followed with the entire line being above grade by the 1920s…

Viaducts are harder to come by these days than they were in the golden age of railroads, and I only know of a few that have been constructed in my lifetime. Despite the hassles that can come along with them, motorists, and likely train engineers too, are happy we have the ones that are here.

Even as railroad lines help put many suburban communities on the map and still provide access to big cities, many local residents just see them as a hassle for the traffic and noise they create. With the automobile dominating suburban travel, trains are nuisance when they block vehicle flow.

I am familiar with numerous railroad viaducts in suburban communities in addition to the ones mentioned above in the south suburbs of Chicago. They were ahead of their time as they allowed access under the railroad tracks, sometimes even before cars were around. Local leaders and officials they foresaw the problems that might arise between ground-level traffic and trains and therefore separated the two flows to let each move on their own. This helps avoid safety issues that still plague communities today.

At the same time, not all of these viaducts have been treated well. As the article notes elsewhere, they can have drainage issues. Their original size is often an issue as today’s vehicles and/or traffic flow is larger, meaning that old viaducts need to be expanded. Letting one car through at a time is better than nothing but many communities would benefit from two lanes each way being able to go under the tracks. Foresight in infrastructure is helpful but it needs consistent attention to keep up with repairs and expanded suburban populations.

Who has returned to the Chicago highways after COVID-19 is a little different

As traffic returns to pre-pandemic levels across the United States, data from Chicago suggests the composition of vehicles has changed a bit:

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Travel times have already returned mostly to normal on Chicago’s expressways, according to the Illinois Department of Transportation. On the Eisenhower, it’s taking drivers an average of 40 minutes to get from Wolf Road to the Jane Byrne Interchange during morning rush hour, compared with 32 minutes in June 2019. Drivers taking the Kennedy from downtown to O’Hare International Airport in the afternoon spent about an hour on the road in both June 2019 and 2021.

Who’s on the road might be changing, though. Truck traffic is up, and more people are working remotely. Among those heading out, more people who were taking public transit before the pandemic seem to be driving, IDOT spokesman Guy Tridgell said.

On one hand, more people are working from home. On the other hand, another long-term change might be that those who used to take mass transit regularly will not go back to that for a long time or ever. What will it take for mass transit ridership to come back to pre-COVID-19 levels? When will people feel comfortable again on trains, buses, and subways? Multiple cities are trying to address this but, as I argued last week, mass transit is already is less preferable for many commuters even before COVID.

Imagine a post-COVID-19 traffic nightmare: trucks all over the place delivering goods as the economy continues to rebound. More cars on the roads because of fears about mass transit. People who were home for months and/or were used to less congestion on the road now stuck in worse traffic. Are there any good short and long-term solutions to addressing this while the mass transit efforts also continue?

Trying to keep up with growth in housing and jobs, Dallas edition

A report on the growing numbers of housing and jobs in the Dallas metropolitan area over the last decades highlights the connection between the two:

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From 2010-2020 the Dallas-Fort Worth metro area added 438,000 new housing units, increasing the housing stock by 18%. Dallas’s growth in new housing ranks No. 9 fastest among the nation’s 100 largest metros, Zillow’s stats show.

Over the same period, Dallas added 802,000 new jobs, an increase of 29%. A healthy housing market should add a new housing unit for every 1-2 new jobs as the local economy grows, according to the Zillow report and industry rule of thumb

.In Dallas-Fort Worth, 1.8 jobs have been added for every new housing unit, indicating that the area is building enough new housing to keep pace with demand, according to Zillow, although many realtors, homebuilders, and would-be buyers argue that’s not the case, at least right now.

Many American communities would like to have this problem: more residents and more jobs. Growth is good. Yet, growth in one area that outpaces the ability for other areas to keep up could become a problem.

In this case, the issue is housing. A flood of new workers could lead to higher demand for housing, driving up prices and increasing competition. In the long run, this could be discouraging both to new workers as well as long-term residents who find themselves in a different housing market.

I could imagine other issues in the Dallas area and elsewhere where growth happens. Take schools. This often comes up in booming suburbs where new residences are plentiful. This puts a strain on local schools and construction has to take place rather quickly to avoid having a lot of students in temporary settings. But, at some point, population growth will slow down and then there might be too much education infrastructure and costs that are difficult for the community to sustain.

Another example could be traffic and congestion. Adding all these jobs and housing units means many more people have to travel between them. Can the current roads and mass transit (roads in the case of most American metropolitan areas) handle all of this? New lanes can be added but putting in additional roads or highways is expensive and time-consuming. And studies show that adding road capacity just leads to more driving and more traffic.

The Dallas area might be fine in the long-run with roughly 1.8 new jobs per new residence but it will take some time to catch up with and settle in to the growth.

Driving down, traffic deaths up in Illinois and across the US

Usually traffic deaths decrease when people drive less. This has not been the case in Illinois or the United States as a whole in the last year:

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About 1,166 people died in motor vehicle crashes in Illinois in 2020, a nearly 16% increase over 2019, according to the Illinois Department of Transportation. That’s a provisional number, said IDOT spokesperson Guy Tridgell, since it takes the state agency 12-18 months to finalize annual data…

Speeding and traffic fatalities typically go down during recessions, according to an October study published by the National Highway Traffic Safety Administration. In Illinois, for example, deaths dipped sharply in 2008 and 2009 according to state data, though they’ve been up slightly since…

About 28,190 people died in crashes from January to September 2020, more than a thousand more fatalities than in the same period in 2019, the federal agency estimated. A full annual report is expected to be released in the late fall…

What’s more, traffic deaths nationally were down from March to May, but jumped back up after states began reopening in June, according to the agency’s estimates.

This suggests safety is not solely a function of the number of miles driven or trips taken. How people drive and the conditions matter quite a bit. In this case, the article hints at multiple possible reasons for this jump. This includes speeding, more impaired drivers, and less seat belt use among those hurt.

I wonder if there are several other factors at play. With many public and private locations shut down, did driving become an even more important escape for some Americans? With limited places to go, driving and doing so dangerously could be a kind of release not available elsewhere.

Second, is there a safety feature to a certain level of traffic? With fewer people out, does this encourage riskier driving compared to having to navigate more vehicles on the road? Too many cars likely leads to more accidents but what about too few compared to typical conditions?

Limited solutions to ensuring more long green light stretches of suburban driving

After occasionally finding stretches of hitting all green lights on major suburban roadways, I wanted to consider how these experiences might become more common. Is it possible? Here are some strategies alongside my sense of whether these would help.

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  1. Synchronizing traffic lights. Los Angeles did this a few years ago to help traffic flow. As a kid, I recall sitting in the car in Chicago and hearing tell of how Clark Street on Chicago’s North Side was set up this way: follow the speed limit and a driver should hit multiple greens in a row. This could be harder to accomplish across a range of municipalities and the various traffic volumes intersecting with the main road. Additionally, this might not help much if there is just too much traffic on the road.
  2. Providing more lanes, more driving options. Americans tend to like this strategy: more lanes, more roads equals more space for vehicles, right? Research suggests otherwise: if you add road capacity, drivers will tend to fill that up. Americans like driving in the suburbs and this is not a long-term solution. In fact, road diets may be more helpful: reduce capacity and it pushes drivers toward other options. Furthermore, expanding roads in an already developed suburban area can get quite expensive and may be controversial.
  3. Encouraging more mass transit use, more walking and bicycling, and less driving. If there are simply too many cars, limiting trips would help ensure smoother driving experiences. All of these options are tough sells in the suburbs. It is hard to provide mass transit in a decentralized landscape and wealthier residents are unlikely to use it. Residential neighborhoods might be set up for biking and walking but connecting to other uses – grocery stores, schools, businesses – is often not possible or is dangerous.
  4. Having more employees work from home. This may be temporary due to COVID-19 but could be a long-term solution for traffic and congestion issues. Of course, there may be more people living in the suburbs due to COVID-19.

This suggests that there may be some short-term solutions but the bigger issue would take more time and effort: American suburbs are built around driving.

Major highway projects continue in the year of COVID-19

The old Chicago joke goes that there are two seasons each year: winter and construction. During COVID-19, road construction goes on even with less driving, limited budgets, and the potential for sickness to spread among workers. First, an editorial update from the Chicago Tribune on the long-lasting Jane Byrne Interchange work in Chicago:

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The arrival of 2021 means we’ll soon be in Construction Season Nine of a notorious project that the Illinois Department of Transportation initially said would take four and a half years to complete.

We refer of course to the glacially paced reconstruction of The Jane Byrne Construction Museum. We use that respectful moniker — always capitalize The, like The Ohio State University — for what old-time Chicagoans used to call the Jane Byrne Interchange…

Whatever the reason, drivers who didn’t abandon the interchange years ago have, in recent days, found the final four rebuilt ramps open. Museum work has shifted to the mainline Dan Ryan and Kennedy expressways — although we trust that, somewhere, IDOT also is building a museum wing to house its excuses for the years of delays and cost overruns: poor soil conditions, unhelpful rules from Chicago’s City Hall, mistakes by engineering firms, utility rerouting, the diversion of resources to emergency repair projects elsewhere, and on and on…

Surely you aren’t surprised that the cost has grown by some 48%, from $535.5 million to $794 million. Most museums recruit donors to cover their big projects. The Jane Byrne Construction Museum instead gets public dollars. Which has us wondering how many gazillion gallons of amply taxed gasoline burned into the atmosphere as all those mummified motorists sat and sat.

Second, a group puts together an annual list of road construction boondoggles. About this year’s selections:

Highways often get greenlit for expensive work because they require engineering upgrades or significant maintenance. The projects in PIRG’s least-wanted list go beyond those basic needs. Like the group’s previous boondoggle roundups, this one calls attention to taxpayer-funded projects set to consume environmental resources, cut through existing communities, and lock in decades of new carbon emissions, for what PIRG argues is little payoff in congestion relief or economic growth. The 2020 report arrives as the ongoing pandemic clobbers state and local budgets and dramatically reshuffles travel patterns.

The largest on the list is Florida’s M-CORES project, a $10 billion, 330-mile plan to build three toll roads through rural southwest and central Florida. Dubbed the “Billionaire Boulevard” by critics who characterize the project as a handout to developers, a state task force recently found a lack of “specific need” for any of the roads, which would run through environmentally sensitive areas.

There’s also the Cincinnati Eastern Bypass, a $7.3 billion highway set to loop around the eastern side of Cincinnati. Originally proposed by a local homebuilder as a replacement (and then some) for the aging bridge that leads into downtown Cincinnati, the 75-mile, four-lane bypass is designed to divert trucks passing through the region on Interstate 75, easing congestion for local drivers, boosters claim. But the report’s authors state that the highway is projected to add thousands of new vehicle trips per day, encouraging sprawl and contradicting Cincinnati’s goals to increase “population density and transit-oriented development” and decrease fossil fuel use by 20%.

No highway policy critique would be complete without a contribution from Texas. The $1.36 billion Loop 1604 Expansion in San Antonio would add four to six additional lanes on 23 miles of an existing four-lane highway, as well as new frontage roads and a five-tier interchange with Interstate 10. Texas DOT says that the new lanes are needed to keep up with population growth, but transportation planners say that the principle of induced demand would cancel out the benefits while adding pollution. The PIRG report puts it this way: “Additional capacity causes more driving and congestion.”

These summaries of major highway projects provide good reminders of several features of such undertakings:

  1. They often require years of planning and years to complete. From start to finish, this could cover a decade-plus. They take a lot of effort to get going across numerous agencies, governments, and actors and have their own kind of inertia as they move toward completion.
  2. These projects are often intended to make driving easier. Adding lanes and capacity can also attract more drivers. In a country devoted to driving, these contradictory ideas can go together. And the roads and systems for driving keep expanding and evolving.
  3. The costs are huge and the efforts required massive. Yet, the average driver may think about nothing but the congestion caused by the construction.
  4. When completed, such roads (and other significant infrastructure projects) can be impressive in their scale. (Whether this is the best use of the land or moving people around leads to other arguments.)

While these articles do not address this, are there significant infrastructure projects that drivers and residents would be pleasantly surprised to find that had been completed during COVID-19?

Imagining self-driving car underground tunnels under major American cities

Elon Musk’s plan for self-driving cars to operate in tunnels under Las Vegas appears close to becoming reality:

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On Tuesday, Musk announced on Twitter that, after a full year in the making, The Boring Company’s first operational “loop tunnel” in Las Vegas is “almost done.”…

The Boring Company built a test tunnel in 2018 near its headquarters in Hawthorne, California. A year later, it landed a commercial contract in Las Vegas to build a loop tunnel system for public use. According to The Boring Company’s proposal, the final system will be able to shuttle passengers in self-driving Tesla cars between any two destinations in Sin City within minutes.

Construction of the initial twin tunnels near the Las Vegas Convention Center (LVCC) was complete in May. The system is expected to be ready for public use for the Consumer Electronics Show (CES) in January 2021. But the event has been moved online due to the coronavirus pandemic.

Last month, The Boring Company won a county approval to expand its LVCC transportation Loop to include an underground station at the new Resorts World hotel located at the north end of the Vegas Strip. Ultimately, the company aims to connect all major tourist destinations along the Strip, as well as two terminals of the nearby McCarran International Airport and downtown Vegas.

This location makes sense when tourism is in full swing in Las Vegas. While the airport is relatively close to the strip, it is not necessarily close time-wise and a quick, automated car ride could please a lot of visitors. It is also fun to imagine this in other cities. The tunnels bring to mind memories of playing the Lower Wacker track on Cruis’n USA. Chicago has some of this infrastructure already in place while other cities might be able to convert or expand existing tunnels.

How this could positively affect streetscapes is fascinating. Imagine major American cities with less traffic in their denser areas, more room for pedestrians, more space for properties to extend past the building. Cars would still be in use – just moved to a different plane – but the emphasis on vehicles would be reduced. More streets could be closed, the scale of social life could change (though the towering buildings in some districts would still loom), and the streets would be safer. (I imagine taxis and others might not be pleased to have the business moved underground.)

This is likely a long project to pursue in any city; making big changes underground in many locations is very difficult. It does keep cars around (just more out of sight) and both the money spent to put the system in place and the ongoing commitment to the system could continue to inhibit other options such as promoting mass transit.

Trying to make a better Walmart parking lot experience

I have driven through many Walmart parking lots and while doing this, I often wonder how a better parking lot experience could help avoid regular issues. Here are some of the big concerns:

  1. There are often a lot of vehicles, people, and carts moving around. It is hard to keep track of all the activity.
  2. Depending on the traffic flow of the location, some of the traffic can be routed right in front of the store as vehicles turn in from a street or adjoining parking lot.
  3. At least a few cars always seem to be lingering right at the front doors or nearby, waiting for people.
  4. Carts are strewn throughout the parking lot; most are in corrals but there are often other ones on medians, in parking spots, and even several parking lots over. (Imagine if the Walmart lot had Costco sized shopping carts!)

A few solutions come to mind:

  1. Everyone needs to be very attentive. Having to pay close attention is not necessarily bad for drivers or pedestrians.
  2. It is better to have the majority of drivers enter the parking lot area from the back rather than from the sides and drive directly in front of the store.

I started thinking about this recently after realizing that I have been in multiple parking garages at Target locations but never at a Walmart. In these locations, there are advantages to having the parking further away from the store and/or having the store on a different level from the traffic flows.

Figuring this out could have multiple benefits including: drivers and pedestrians would feel safer, the parking lot experience could be less fraught and more pleasant, and fewer work hours might need to be devoted to the parking lot.

Perhaps this is just the price Americans are willing to pay for their love of driving and sprawl: complicated parking lots. This is not an issue exclusive to Walmart as many big box stores demonstrate similar patterns. But, since Walmart has so many locations and so many customers, solving issues there could be a big deal.

Addressing more Chicago traffic when fewer people take mass transit

With COVID-19, few may be willing to ride mass transit even as everyday life slowly returns to some normalcy. This has consequences for traffic:

man standing beside train

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World Business Chicago, a public-private nonprofit agency that promotes the city, estimates that on a given workday there about 406,000 office workers in downtown Chicago, making it the country’s second-biggest central business district after Manhattan.

Many of those people arrive by trains and buses, with the CTA and Metra providing almost 1.9 million rides combined on an average, pre-coronavirus weekday. That includes 1.6 million total one-way CTA rides and 263,000 Metra trips…

Riders’ hesitation may come in part from the Centers for Disease Control and Prevention’s recommendation in May that people drive to work alone. That guidance rankled public transportation advocates and created concerns of major traffic and environmental impacts in densely populated cities…

“We’re hearing stories from New York and (Washington) D.C. about employers saying if you’ve taken public transportation you can’t come in the building,” Lavin said. “We want to be sure there’s nothing against public transportation here. In order to do that, we need to have a dialogue.”

Chicago has heavy traffic even with mass transit use because it is a transportation center with plenty of highways and intermodal facilities.

As noted in an earlier blog post, this does present an opportunity to reduce traffic long-term or make a choice to continue to rely on a sprawling landscape full of drivers in their own private vehicles. There are multiple options to pursue:

1. More people working from home. This would reduce traffic on major roads.

2. Stagger work times more so that “rush hour” is more spread out.

3. Find ways to make sure mass transit is safe and/or people feel confident riding it. This might require more resources or better PR or new ideas.

4. Pushing for more people to be able to work closer to their workplaces (meaning more housing options throughout a metropolitan region).

5. Pushing for denser areas in the city or suburbs. (This might be a hard sell right at the moment due to concerns about COVID-19.)

6. Providing more incentives for fleets of vehicles (electric or otherwise) so that not every household has so many cars.

Any one of these or several of them could be pursued at multiple levels with actions from individuals, local groups and municipalities, states, regions, and the federal government.