What if we closed Hennepin?

Cross-posted from streets.mn : What if we closed Hennepin?

What if we closed Hennepin?

What if we closed Hennepin Avenue S. to through cars? It is illustrated in the adjoining map.

The Design

Suppose you created a Hennepin Transit Mall, similar to Nicollet Avenue in downtown or Washington Avenue at the University of Minnesota, with room for bikes, pedestrians, and a high-quality fixed-route transit service connecting Uptown with Downtown (with a flyover/short tunnel somewhere to cross I-94).

Hennepin would be closed at I-94 on-ramps, at 22nd, 24th, 25th, and 26th. The closure in my plan would be half-block (or less), enabling the road to still be used for local access traffic, but not through traffic. The space devoted to car movement could probably be reduced to one-lane in each direction from 26th street to Franklin Avenue, with the rest of the space for streetcar/bus lanes and on-street parking, bike lanes, and sidewalks. Where the road was physically closed, there would be a small pedestrian/transit plaza.

Why would we do this?

(1) There are plans to run a Streetcar down Hennepin (forecast to carry 11,000 – 13,000 riders) plus there are existing buses. If the streetcars and buses had a more exclusive right-of-way, they could provide better service and carry more riders. The road is not able to accommodate the streetcar (at current standards of design and levels of service) and all the existing traffic. If the community truly wants transit to be the primary mode from Uptown to Downtown, the Right-of-Way needs to be turned over to transit.

Streetcars will make left and right turns awkward at best, especially with high traffic counts. Current vehicle traffic counts on Hennepin (2011) are 25,927 two-way at Hennepin just north of 25th street. Lyndale currently carries 14,680 two-way just north of 26th street (though the counts on Lyndale are highly variable, and just a few blocks north it supposedly carries 24,000).[I don’t believe that if we closed Hennepin, all of that traffic would switch to Lyndale, though certainly some would].

(2) Hennepin creates a large number of awkward intersections even in the absence of a streetcar. It violates the existing street grid. It is congested. There is a case in the transportation literature called the Braess’s Paradox which says under certain circumstances, removing a link can save overall travel time. I do not know if Hennepin is such a case (and even if it were, it might only be under certain traffic conditions), but the congestion creates spillovers. There are other paradoxes in transportation about traffic signals, and so on, but the main point I think is that this added capacity is less valuable than elsewhere because of the awkwardness of the network. Roads and cars have problems when intersections are not at 90 degrees and have more than 4 legs. To fix that, traffic engineers at some time in the past further bent the street grid.

New York had this problem with Broadway, which cuts a diagonal through the regular street grid. Its solution was to close it to through traffic i.e. to disconnect it in many places.

(3) More capacity leads to more traffic, less capacity leads to less traffic. This is the phenomenon of induced demand, and is well established, the best local example for which we have evidence is the case of the I-35W Bridge after its collapse.

(4) Closing Nicollet to private vehicle traffic downtown has not seemed to hurt economic activity there.

Why would we not do this?

(1) Lethargy.

(2) Businesses on Hennepin will complain. Neighbors on Lyndale will complain. [Businesses on Lyndale might quietly rejoice with the additional traffic though]. Change is hard.

(3) Removing the link will increase distances for drivers who continue to use their cars to travel between I-94 and Uptown. My estimate is total distance per trip will increase by less than 800m (0.5 miles) for cars, as the hypotenuse does not save more distance than that, depending on where you are going.

(4) Hennepin is the next major arterial at the approximately 1 mile grid spacing, removing it would maim the arterial system. [Comment, since Lyndale and Hennepin come together at I-94, the arterial system is largely ineffective anyway.]

What would happen?

Based on evidence about induced demand, some traffic would disappear and some traffic would reroute to alternatives. Substitute routes should see an increase in total traffic. My guess is the most affected route would be Lyndale. If my posited design were implemented, short sections of 22nd, 24th, 25th, and 26th Streets would also see more traffic as travelers from the North peel off from Lyndale to reach places on Hennepin that would have been accessed differently.

There would be fewer traffic conflicts at the remaining Hennepin Avenue intersections, though it wouldn’t go to zero, as sections of the route would still be open.

It gives us an opportunity to straighten the grid. Colfax, Dupont, and Emerson can be reconnected as through routes. We can also remove or modify a number of the traffic calming measures in the neighborhoods abutting Hennepin, as the spillovers would be of a different nature.



The Elements of Vibe

What is vibe? Vibe is the vitality of street life, the feeling that there is something going on, of being where the action is. Successful places have vibe, dead places don’t. We don’t want vibe everywhere and probably can’t support it. But surely we could have more active places then we do now with a better location of activities.
We drive to places we can walk around, rather than walk around our own neighborhood, unless we happen to live in a place with vibe.
Why do we want to walk around? Because there are multiple things to do: find food, browse books, hear music, entice the intellect, stimulate the senses. This concentration of activities only happens because of the crowds around, and the crowds only gather because of the concentration. More begets more.
These are ‘economies of agglomeration’ as the economists might say or perhaps ‘network effects’. But they allow for the spontaneous walk-in business rather than the planned trip. Many businesses are unlikely to attract spontaneous walk-ins, for instance vacuum cleaner repairs, [I don’t normally walk around with a vacuum cleaner on the hope I will find a repair shop] and thus lose little by not being located in the center of action and save much on rent. Some restaurants are so good, they require a reservation, and thus there is little spill-in traffic. But other businesses, by saving on rent, are foregoing additional business.
Moreover, those businesses are denying potential spillover traffic to their would-be neighbors. It is a calculation that proprietors must do for themselves, but there is a coordination function that a good entrepreneur can serve, matching businesses that attract walk-ins with compatible stores, and maybe subsidizing (lowering the rent for) those that generate more spill-over traffic than they attract.
There are three seeds:
* A concentration of people (customers, though they need not be spending money, that helps)
* A concentration of stuff (suppliers, who need not be selling)
* An environment that encourages people to spend time doing stuff (marketplace)
People concentrate for a variety of reasons – to exploit the material resources of the earth, to have safety in numbers, to find a pool of potential mates, or simply because it is at the intersections of routes between two other places. These intersections (nodes in transportation lingo), create opportunities. In the streetcar era, people might change lines at a node, and those pedestrians would create the streetlife necessary to support new businesses. In the highway era the scale changed, and nodes are the interchanges of freeways. Businesses, and especially shopping malls, take advantage of these points of high accessibility. But the shopping mall is now clearly the destination, not a side-product of a transfer point in the same way street-car corners were.
Some further assertions about human nature:
People like pleasant climates – dry, not too hot, not too cold, clean air, not too loud.
People want to feel safe – they don’t want a car careening out of control disturbing their sidewalk café meal, they don’t want to think they will get run over crossing the street.
People are lazy – they don’t want to walk too far to get where they are going. If they are driving, they want easy convenient parking near their destination. They like to cross the street midblock and don’t want to have to walk to intersections.
People are cheap – they don’t want to pay for that easy convenient parking, they prefer lower to higher prices for the same good.
The last two be summarized by the idea that “People take the path of least resistance�?.
Observing cities around the world with an informed, but casual analysis leads me to assert some rules about the environment that lead to vibrancy.
Buildings on the sidewalk – vibrant areas have buildings that abut sidewalks with not large gaps between the building and the walk. The density of activity is necessarily reduced by space between building and path (and thus other buildings).
Sidewalks on the street – to have vibe, sidewalks must abut the street, or *be* he street in pedestrian only areas. Pedestrian only areas can work, and anyone who says otherwise has other interests at heart. This does not mean that they will work, but given the right environment, people would prefer to shop without having to look out for motorized vehicles.
Streets move slowly – fast streets make pedestrians feel unsafe, and thus reduces the benefits of being on the sidewalk. Ideally streets are moving at pedestrian speed in the pedestrian area. Of course streets leading to the pedestrian area move faster, or people could not get there.
Vehicle space on the street is minimal – wide streets increase the distance pedestrians must walk to reach other activities. Narrow streets give access to more stuff in less time. Hence the reason many enclosed shopping malls work better than many shopping streets is the density of stuff is fairly tight.
Street two way – One way streets may not be inherently problematic, but one-way streets are generally that way to move more vehicle traffic faster through the area, which is the opposite goal of moving pedestrians between buildings within the area.
Opportunities to explore just around the corner – hidden (pleasant) surprises are one of the things that make cities interesting to be in, if I go around this corner what will I discover. The same opportunities do not exist in an enclosed shopping mall, where everything is pre-mapped and tightly controlled, and I know each “block” ends at a parking ramp. Hidden unpleasant surprises however are one of the things that can kill a city, I don’t want to experience dread when I walk down an alley attached to my favorite shopping street.
This set of rules is by no means complete, but rules like these created streetlife in streetcar era places, and they create vibe in the better shopping malls.