This 2018 Study using 30 years of data for 89 US metropolitan statistical areas (MSA) stated: “In fact, the results suggest a positive association between traffic congestion and per capita GDP as well as between traffic congestion and job growth at the MSA level.”

When you are next in a traffic jam, you could say to yourself, this is good for the economy.

However, depending on your attitude, it may not be good for your mental well being or, for society overall. Something you may want to consider the next time you hear a politician say something is good for the economy.

When I did a Google search on “traffic congestion good for the economy” I found most of the results where about traffic congestion slowing down economic growth.

Ther is a distinction between what is good for the economy and slowing economic growth. A driving analogy would be if you are driving at 200 kph and you change your speed to 199 kph, you have slowed.

Apparently no matter how small economic growth, slows, it is bad, according to economists

All theory on my part, but possibly because of the concept of profit motive.

Accountants recon that profit is the difference between income and expenditure. If a business wants to make a certain profit percentage, then they add that to ther costs. Therefore, at any profit percentage, the higher the cost, the more profit. Business are all about maximizing profits.

When traffic is congested it cost business more to move goods and provide services. Add the profit percentage to those higher costs, hence, business make more profit. Business then pay more tax to government that spend it on the community. The community then spend that money on purching goods and services that business provide. An so it all goes around again. Thats why, in my opinion, the profit motive, makes traffic congestion good for the economy.

Because of traffic congestion, voters complain to politicians who spend some of the taxes that have been collected on building or expanding the road system. No matter how much more is added to the road system, reasonably quickly the traffic congestion returns. The voters complain to the politicians again, and the cycle repeats its self. But the traffic congestion does create jobs and ancillary jobs, for those making the roads.

According to this article cars are only used 5% of the time meaning they are parked 95% of the time.

When cars are used, even though they have an average carrying capacity of 5 people they typically only carry an average of 1.5 people in the US and 1.45 in Europe, with this trending down in both locations.

Of all time available on all roads 6,864,336,000 hours kilometres, 873,600 km of roads X 24 x 365, only a very small % is utilized in moving people in Australia. Its extent is unknown but has been estimated in a report, Revenue from road use

New manufactured cars can be transported great distances across oceans

In Australia Passenger carrying vehicles were comprised of 93.8% passenger vehicles, 5.7% motor cycles and 0.6% buses

In Australia the average Car travels 12.1 thousand kilometres per year, even though it is physically possible to travel many times more than that.

The average age of passenger cars is 9.8 years in Australia, even though cars can last a lot longer than that. That link “BENEFITS OF REDUCING THE AGE OF AUSTRALIA’S LIGHT VEHICLE FLEET Summary report - December 2017” by the Australian Automobile Association has a sub title of “Economic Connections”

The average fuel consumption for passenger vehicles is 11.1 compared to motorcycles of 6.1 liters per 100 Ks, yet both can transport the average people per vehicle. Both are higher then the best possible fuel consumption.

the average car size increasing

Note: Most of the above links are for different countries and different time periods, such that exact comparisons can not be made

The concussion from this incomplete list is that the current system for transporting people is very inefficient, creates traffic congestion, that is good for the economy but is bad for the well being of society.

The present economic system of mainly concentrating on growth without considering who benefits from that growth would appear to be the problem.

The Economy of Well-Being as espoused by the OECD, might be a better alternative.

Demand–side approaches are needed to help address transportation issues created by growth.

Rather than building more roads it could be better instigate actions to reduce the discretionary demand for people transportation.

Some articles:

Traffic congestion is a handbrake on economic growth

How Traffic Congestion Affects Economic Growth

Insights into the socio-economic impacts of traffic congestion in the port and industrial areas of Chittagong city, Bangladesh