Tuesday, April 21, 2015

Transit versus the overly-accessible freeway

In the run-up to construction of the Green Line between Minneapolis and Saint Paul, neighborhood activists spent a huge amount of effort to get three extra stations included on the route at Hamline Avenue, Victoria Street, and Western Avenue. These extra stations cut the distance between stations in half on that section, from one mile down to half a mile. This put nearly all of the buildings that face the Green Line on University Avenue within a 5-minute walk of the stations.

Getting that change to happen required advocacy work all the way up the chain of command for transit projects in the United States. In early 2010, the Federal Transit Administration changed the rules to de-emphasize a calculation called the Cost-Effectiveness Index (CEI) while adding an option to include livability as a factor. The change didn't just affect the Green Line, but meant that any other projects around the country could also benefit.

Considering that tremendous battle, it's amazing to see that on-/off-ramps to surface streets on Twin Cities freeways—the car equivalent to stations on a transit line—are often spaced less than a mile apart. In the map I made above, around 40% of the area's ramps are spaced one mile apart or less, and the great majority—about 85%—are less than two miles apart.

The shortest distance I found between two full interchanges is in Golden Valley by the headquarters for General Mills. It's about 0.3 miles along Highway 100 between Olson Memorial Highway (MN-55) and Shelard Parkway/Betty Crocker Drive.

The ramps at Shelard/Betty Crocker are also very close to the interchange between MN-100 and Interstate 394, though in making the map, I ignored exclusive freeway-to-freeway interchanges, since they don't provide any access to surface streets.

The longest stretch of closely-spaced ramps appears to be along MN-36 between Cleveland Avenue and Lexington Avenue—five interchanges on a two-mile stretch of highway, each a half-mile apart.

Now take a look at this presentation board from the Robert Street Transitway study and the station spacing suggested for each mode. It's head-scratching to see these ranges and compare them to what we expect when building infrastructure for cars.

For highway bus rapid transit services in particular, the suggestion is to space stations about two miles apart. There isn't necessarily anything wrong with that, particularly when highway BRT is laid on top of a system that already has closer stop spacing, but it is striking to compare it with a freeway system where most interchanges are much more tightly spaced.

I'm of the opinion that most of the Twin Cities bus network has stops that are packed too close together—usually around 1/8th of a mile apart on local routes, and sometimes even less. This isn't a huge problem on less-used and less-frequent routes, but busy lines are made interminably slow when they need to stop every block (and sometimes even more often than that!), but buses that run every 10 minutes or less are typically busy enough to need their stops spaced out a bit.

Two main problems arise when transit lines have closely-spaced stops: First, passengers get on and off at stops that are as close as possible to their destinations (good for them, but not always so good for the system). Second, passengers can end up making nonsensically short trips, such as waiting 5 or 10 minutes for a bus that will take them a quarter-mile down the road—a distance that can be walked in 5 minutes.

Limiting the points of access reduces those issues and makes for smoother trips. Yes, it is an inconvenience for some, but it tends to provide benefits to far more riders than it hurts.

Would similar effects be possible by spacing out some of our freeway access points? Can traffic congestion on highways be alleviated by encouraging some of the extremely short trips to happen on surface streets instead?

In urbanized areas with valuable land, this might be a simpler and better alternative to highway tolling, which have historically required toll plazas (difficult to fit into urbanized areas, although they are less necessary today due to RFID and other technologies that don't require physical payment).

Interstate 94 between downtown Minneapolis and downtown Saint Paul has a fraught history, but it probably has one of the region's better designs. Ramps are mostly spaced about a mile apart, with additional roadway crossings every half mile and pedestrian bridges in between those. There's a crossing of some type almost every quarter mile.

Freeways can provide a great improvement in travel speeds, but designers have often been too focused on providing more car access to the freeway than improving the ability for people in all types of traffic to get across freeways or around and between nearby neighborhoods.

Some ramps should be removed, though in most cases the bridges crossing the freeway should be maintained. The bridges could also be reworked to add new freeway BRT stops, like the 46th Street station along Interstate 35W in Minneapolis—rather than removing access, it would change the type of freeway access from automotive to transit. In the long term, that would improve the overall throughput of the freeway system by getting more people into high-capacity vehicles.

Looking the other direction, our region's current pattern of freeway ramp spacing should provide some lessons to transit planners. Even though the primary mode of transportation on the highway is by car, the spacing varies significantly in response to geography and the surrounding development pattern.

In my mind, it doesn't make sense to say that commuter rail should only stop once every 7 miles, as shown in that display board—many parts of the world have "commuter" trains that stop about as often as our Blue Line light-rail service. Transit planners should be more adaptive and do what's right for a particular corridor rather than sticking too close to an often-arbitrary modal definition.

Besides, how can we expect people to switch to using buses and trains more often when it's harder to reach them than it is to get to the nearest highway? These are some of the questions we need to consider as we work to ensure a stable footing for the future of the region.

Monday, April 6, 2015

Following the tracks to Duluth

Here is a map showing the route for trains that are expected to run from Minneapolis to Duluth once the Northern Lights Express project is completed. Like my previous map for Amtrak's Empire Builder, this shows segments of single- and double-tracking (usually sidings) along the corridor. This highlights the places where trains may be able to pass each other, and gives an idea of how much capacity there is on the line.

There aren't any regularly-scheduled passenger trains on this route today. Amtrak stopped service in the 1980s, though there are usually one or two excursion trips per year operated by the Friends of the 261.

Ever since Amtrak stopped running on the line, there have been efforts to restore passenger service to Duluth. The Northern Lights Express (NLX) is the current project, which is in the midst of Tier 2 environmental review and preliminary engineering.

The Northern Lights Express is planned to have several daily round-trips and end-to-end travel times somewhere between 2 and 2½ hours. On existing tracks, the route is about 153 miles, though abandoned track in and near Duluth has caused the route to become a bit more circuitous than it used to be. Today, the trip would be about 4 miles longer than what it was for earlier passenger trains on the route.

Bridges at the mouth of St. Louis Bay in Duluth
as seen in 1961.
Timetable of Great Northern trains to Duluth from 1966.
A notable change in Duluth was the abandonment of bridges across the St. Louis Bay which ran near the Blatnik Bridge (Interstate 535/U.S. 53). Both of these were taken out in the 1980s. Farther south, there was also a realignment the main line leading to a junction at Boylston, Wisconsin. Today's Target Field station in Minneapolis is also about half a mile farther south than the old Great Northern depot, which was demolished in 1978.

There used to be a few competing services running between the Twin Cities and Duluth—the Great Northern from Minneapolis (today's route), the Northern Pacific from Saint Paul (closely followed by Interstate 35 today), and another route from the Soo Line which ran further east. Both of these latter two routes have seen big segments of track be abandoned, so they aren't practical for reuse without huge investments.

In the 1950s and 1960s, each railroad operated one or two trains per day on their line to Duluth, so their were about 5 daily round-trips in total. To the right is a Great Northern timetable, which shows the express Gopher train and the local Badger. Both trains ran through Minneapolis and terminated at Saint Paul Union Depot, but for comparison's sake, I'm going to ignore that last leg.

The express Gopher train took 2 hours 50 minutes northbound from Minneapolis to Duluth and 2h45 southbound, while the local Badger took 3h10 northbound and 3h05 southbound including all of its extra stops. Over the distance of 149 miles, the average speed ranged from 47 to 54 mph across these different trips.

When Amtrak took over the nation's passenger trains in 1971, Duluth was initially cut out of the passenger system, but service returned after several months. Frequency ranged from one round-trip per day to only a few round-trips per week, down to about one-tenth as much service as there had been a couple decades earlier if all three railroads were counted. The service finally ended in 1985.

What will it take to get passenger service restored to Duluth?

Great Northern successor BNSF Railway owns the tracks today, and there are about 17 daily freight trains on the route according to MnDOT. The same map shows a current speed limit of 50 mph, though it's unclear if passenger trains would be restricted to that same number (passenger trains are typically allowed to run 10 to 20 mph faster than freight trains on the same tracks).

Between Coon Rapids and Boylston, the average single-track section is about 10 miles long. There is one 16.3-mile section of single-track between Cambridge and Grasston which limits capacity. Another 20-mile section between Andover and Cambridge only has short sidings and might be considered as one segment of single-track.

Excepting a couple of short outliers, the average passing siding on the route is about 1.6 miles long, or around 8,450 feet. Freight trains can be up to around 7,000 feet in length, so there are some sidings where they are a tight fit.

The 20-mile section from Andover to Cambridge probably limits rail traffic to about two trains per hour at current speeds. There's an upper limit of about 48 trains/day on this line, though that would require a completely even distribution of traffic at all hours with each train operating at a consistent and relatively slow speed.

The most likely plan I've seen for NLX has had 8 daily round-trips. Adding 16 passenger trains to the existing 17 freights would result in 33 trains/day, and that's with a mix of trains operating under different speed limits. The line definitely needs some improvements to handle that much traffic and leave enough headroom for schedule slips and other disruptions.

It may make sense to double-track the entire corridor someday, though some early estimates for doing that ended up with $1 billion-plus cost figures.

Lengthening the short siding in Bethel and adding another near Stanchfield would chop the longest non-passing segments in half. Combining that with lengthening some existing sidings and adding three or four others would probably double the line's capacity, making it far easier to add passenger trains to the route while maintaining the ability to move freight and keep everything running on schedule.

Based on this cost estimating methodology from MnDOT, adding these sidings would be relatively inexpensive, probably around $40 million. However, since higher speeds are needed on this line to attract as many passengers as possible, it would only be one modest component of the total cost.

It's possible to dial the expenditures up or down on the route in order to target a "sweet spot" of benefits versus costs. As I mentioned in a post last month, if a passenger service is able to control its operating budget properly, it should be possible to pay off infrastructure cost through fares.

Previous studies have suggested that the Minneapolis to Duluth corridor could attract 900,000 or more annual rail passengers if the speed and frequency of service were high enough. This puts the Duluth line at or near the zone where it could make sense to for a private operator to put in around $2 million per mile, or around $300 million total, particularly if they received a low- or no-interest loan for the buildout.

It would be a challenge to construct a fast, frequent service for that amount, but might just be doable. But even if federal, state, and local governments had to cover the remaining amount in a public-private partnership, it could accelerate development of one of the most important transportation links in Minnesota.