I started wondering about other variables that might affect pavement condition index (PCI) in the council districts, so here is a little more exploration. See the previous post: pavement condition in Sac City.
First, the council district map, for those who may not be familiar with boundaries.
I wondered about the relationship between population density (people per square mile) and PCI. There isn’t any correlation, though again, the district 1 and 8 outliers may be interesting. I did not realize that district 8 has the highest population density of the districts.
I wondered about the relationship between lanes miles and PCI. There is a weak correlation.
And finally, here is my current data table, in case you want to play with data or suggest insights. Note that the population of each district is roughly the same, as it should be. The unfunded column is the amount (millions of dollars) of backlog, to bring roadways up to PCI 75, but it does not include the ongoing yearly expense of maintaining them at that level.
In the search for other information, I came across the City of Sacramento Pavement Condition Report, dated March 2020, and it has some interesting things to ponder. The city has 3000 lane miles of streets. The county reports road miles instead of lane miles, so I can’t directly compare the city and county, but the city does say it has the fifth largest roadways network in California.
The report has maps for each council district, showing the PCI for each (PCI = pavement condition index, a measure of how well the roadway has been maintained, higher is better). I wondered whether the PCI correlated with income, as many things do, so I plotted 2020 median household income of each district against PCI, table and chart below.
There is not a strong correlation between income and PCI, R = .42, but district 1 and 2 are clear outliers, with 1 being the highest income and highest PCI, and 2 being the lowest income and lowest PCI. The city report says that the reason district 1 has a high PCI is that the roads there are newer, but I’m a little doubtful this explains it all, since many of the roads in that area are now old enough to need maintenance.
The target score for ‘roads in good condition’ is at least PCI 75, so Sacramento is falling far short of that because it is not spending enough on roadway maintenance. Part of the reason for this is that money is spent on building new roadways and widening roadways instead of maintaining roadways. But the underlying reason is that the city has allowed to be constructed, and then taken on maintenance responsibility for, roadways which it does not have the income to maintain. In new developments, construction of internal roadways is paid by the developer, but arterials and collectors, which often must be upgraded to handle increased traffic, and the interchanges with freeways, are largely paid by the city, or grants, and are maintained by the city. But low density development, of which the city was formerly very fond and still has some attachment to, cannot ever generate enough income in property or sales taxes to maintain the roadways. This is one of the great suburban subsidies that so hurts our cities and counties.
The report lays out three funding level scenarios:
current funding levels: The PCI will deteriorate over 10 years to 42, which is rated ‘poor’, and if ever corrected, would cost about ten times as much to correct as it would to maintain. I doubt that most people in the city would find this in any way acceptable.
maintain current conditions: To keep the PCI level at 60, the city would need to spend $35.7 million per year, but it is currently only spending $9.7 million per year. This is 3.7 times current expenditures. Though the PCI would be stable, there would be a continuous increasing backlog of maintenance because the PCI would not be improved to the desired 75.
improve conditions to state of good repair: To bring PCI to 75 would cost $58.5 million per year. This is 6.0 times current expenditures.
What to do? I’m sure if the city knew, it might never have gotten into this bind. This is a pattern with nearly all cities, that they cannot under any reasonable current taxation scheme hope to maintain their infrastructure. This post is about roadways, but the same is true of water supply and sewer and electric and gas. And services such as fire and police, for that matter. And it doesn’t even touch on the need for sidewalk maintenance, which is only addressed in terms of adding ADA structures at intersections. For much greater insight on the problem and possible solutions, I refer you to Strong Towns and the book Strong Towns: A Bottom-Up Revolution to Rebuild American Prosperity (from your local bookstore or library).
But I will suggest some things:
a moratorium on accepting any new roadways into the city, until the city has identified a mechanism for maintaining them, which would probably entail the developer paying into a trust fund for maintenance
paving of parking lanes to a lower level of maintenance than travel lanes; adjacent areas do not need the load bearing capacity of travel lanes nor receive as much wear and tear; the city has already done this in a few locations
reducing excess travel lanes; for most roadways in the city, three travel lanes per direction are excess capacity, rarely needed except for brief periods of time or in uncommon circumstances; though re-allocation to bike lanes, separated bikeways, or sidewalks (or in a few cases, parking) should be the ultimate fate of these excess areas, in the meanwhile they can just be blocked off from use and therefore remove the need for maintenance; in many cases two lanes per direction are also excess
evaluate whether a lower PCI than 75 might be just fine for residential streets and collector streets; after all, poor pavement does have a traffic calming effect, and we need traffic calming everywhere, so maybe PCI 60 is OK for many roadways
I believe that funding to maintain local streets, most of which are residential streets, and probably collector streets, should come from the city or county level, not from the state or federal government. The closer to the roadway the funding is, the more likely the city or county is to make rational and sustainable decisions about roadway maintenance responsibilities and funding. I think an argument could be made that arterial maintenance should be funded by the state since these roadways serve traffic beyond the city and county boundaries.
As a car-free person, you might assume that I don’t care much about pavement condition, but buses and bikes operate on the same streets as private motor vehicles and commercial vehicles, so acceptable pavement condition is important to me as well.