Overpass vs. underpass pedestrian psychology

[nerudite]

We are looking at various options of linking the pedestrian network on two sides of a new highway that is being developed in town. Part of the discussion this morning centered on pedestrian safety and preference regarding overpass vs. underpasses. One of my colleagues mentioned a psychological study and report comparing how safe people feel using an overpass vs. an underpass. Although I've done a little googling to try to find said study, I've come up with nothing. Anyone know of a source for this type of information?

[gkmo62u]

Sorry, have no sources, just perception. Underpasses are seen as unsafe, damp places where teenages loiter and smoke.

[plankton]

http://www.forttosea.org/

This project includes an underpass. It is in a rather rural area (so maybe not applicable to your situation) but does cross under a major highway (US Hwy 101) and has been received positively by the community. Perhaps the National Park Service conducted a study that would be of some value to you.

In my opinion, installing motion-sensored cameras would be a must for most urban underpasses being proposed today.

[Coragus]

In my experience, public opinion seems to be that underpasses are considered unsafe due to crime, especially if they don't go straight through. On the other hand, underpasses don't have an effect on those who are scared of heights. I don't have any studies to support this, just public comments.

[Margin Walker]

there might be something in some of these reports:

http://www.vtpi.org/documents/walking.php

The perception will depend on the design. Is it a relatively flat area where an underpass or overpass would mean that the pedestrians would have to descend or ascend a set of stairs to cross? How long would any tunnel under the roadway be? and can you easily see through it (wide and open) to minimize the perception of both a tunnel and an unfriendly place.

At the university I attended there was a major pedestrian crossing at the very top of the hill that resulted in several accidents while I was there. The university proposed lowering the roadway and building a bridge for pedestrians/bikes and the internal transit system at what originally was ground level. The design was trying to minimize the tunnel/bridge look as much as possible and I thought it was a great idea. The city didn't like the idea of having to go through a "tunnel" to enter it though.

[JNA]

Have you looked at
FHWA’s The Pedestrian Facilities Users Guide
http://www.walkinginfo.org/pdf/pedus...duserguide.pdf
6 . Pedestrian Overpasses/Underpasses . . . . . . . . . . . . . . . . . . . . . . . . . .49


WISCONSIN BICYCLE FACILITY DESIGN HANDBOOK
http://www.dot.state.wi.us/projects/...e-facility.pdf
Table 4-12: Overpass and underpass considerations
Overpasses
Positive:
• Good visibility from surrounding area
• Light during the day
• Open and airy
Negative:
• Typically requires greater elevation change than underpass
• Bicyclists use energy to go up, gain it back coming down
• Open to the elements
• Vandals may drop or throw things onto road
• Some users may feel vertigo
• Bicyclists attain higher freewheeling speeds making ramps
more difficult to negotiate and design
Underpasses
Positive:
• Protected from weather
• Bicyclists gain energy going down, lose it going up
• Change in elevation is likely to be less than with overpass
Negative:
• Can be dark, damp, and intimidating (fig. 4-115)
• Users may not be able to see through to other side
• Some users may feel claustrophobic
• Criminals may hide, waiting for path users

Other sections worth looking:
4.15.7 Grade separations ........................................4-69
4.16 Shared-use path structures............................ 4-71
4.16.1 Bridges and overpasses ................................4-72
4.16.2 Underpasses and tunnels ..............................4-75
4.16.3 Combining structures ................................... 4-79
4.16.4 Separation on Combined Structures................4-81



Pedestrian Safety Guide and Countermeasure Selection System
Pedestrian Overpasses/Underpasses
http://www.walkinginfo.org/pedsafe/p...gFlag1=1&X=998

check out the case studies listed.

[ssnyderjr]

JNA, glad you gave the FHWA some props. For the most part, they are the national authority for most guidlines and studies related to traffic.

I would also add that it would depend on what you are overpassing/underpassing. If you are attempting to overpass another road, you may want to consider vandals dropping items off the overpass onto cars below. Toledo, OH had an overpass where some kids dropped a steel plate off of it and it killed a driver. If you are overpassing water it may be scenic. If you are overpassing RR tracks, that would be the way to go, since the RR would have to spend money to re-route their tracks which could be VERY expensive.
Also your soil type could be constrictive. In our city, bedrock is 3-6' deep throughout town and makes underpasses cost prohibitive, with the need to dynamite rock and excavation.
Maintenance (especially in snowy regions) plays a big role also. Overpasses typically need plowed more often (cause they freeze first being exposed to the elements).
Another constraint could be drainage, if you are near the water table, many pumps and piping are required for underpasses.
The last factor you may want to consider is displacement of homes, typically overpasses takes more RW and houses due to embankment, whereas pilings can be driven and minimal RW is required for underpasses.

Consider housing (displacing homeowners), soil types, drainage, maintenance and your budget allowance when choosing an overpass over an underpass. Keep this in mind that before considering pedestrian perception. From my experience, overpasses are generally more intimdating for people to climb/bike who are not in good physical condition. If it takes too long to go over an overpass, people will opt to cross at-grade which can be dangerous. We have a RR overpass where ped's cross 2 sets of high speed tracks at-grade because our pedestrian bridge takes too long to climb.

[JNL]

I'm sure I have seen something on this. I just checked through a list of references and I think this book may be useful but I can't recall if the recommendations are based on research. I will look for other references.

TITLE:CRITICAL PATHS: DESIGNING FOR SECURE TRAVEL
AUTHOR/S:ATKINS S T
DATE OF PUBLICATION:1989
SOURCE/PUBLISHER:THE DESIGN COUNCIL
ISBN:850722799
NO. OF PAGES:96
ILLUSTRATIONS:YES
DOCUMENT TYPE:BOOK

"Highlights the importance of well-designed, safe connections between pedestrian and transit systems. Includes design recommendations for pedestrian subways, if they must be used."

(reference is in this format because I pasted it from a spreadsheet of literature I reviewed)

Edit: found this UK reference to research http://www.dft.gov.uk/stellent/group...503822-17.hcsp (google search terms: pedestrian perception subway research)

[green22]

JNA, glad you gave the FHWA some props. For the most part, they are the national authority for most guidlines and studies related to traffic.

The good news is that many FHWA specifications are either flexible or merely suggestions. The bad news is that so many planners use them as their prinicipal guide.

I agree that as planners we must ban all behaviour which could possibly be dangerous. In fact I propose that we take a look at our accident data to find out the sources for the incredible carnage on our roads today. Once we identify this source of dangerous behaviour we must ban it; whether it is pedestrians crossing highways or perhaps other vehicles.
Making all pedestrians travel under freeways for supposed safety concerns would just add one more challenge to being a pedestrian in America.
A less drastic solution to this rare problem was the caged or fenced pedestrian overpass. Of course these have their own safety / attractiveness issues which would likely affect the amount of potential users.

[The One]

Here's an idea, why not UNDERPASS the stinking road and put people back where they belong....ahead of cars Keep the people at grade and subject vehicles to sub-terrain conditions

I'm on edge about pedestrian connectivity.....My family and I ate dinner at an Applebees last night and we wanted to walk directly across the street to the Barnes and Noble.....Had to walk 200 feet against traffic to get to a spur sidewalk then cross 8 lanes of traffic only to find no direct pathway to the book store, so we broke out the machetes and plowed through all that wonderful (well landscaped) area between us and the store....then battled parking traffic to enter the store.....

[Random Traffic Guy]

The One's got the idea, if you've got the cash for it.

A while back I worked on the Pedestrian Passageway at Texas A&M University. This is an underpass that links two sides of campus, and more specifically a 3,500-space parking garage with Kyle Field, bypassing a 6-lane (I think) arterial and RR tracks. This was replacing a generally-unused old-fashioned overhead crossing and at-grade crossings that produced pedestrian-vehicle crashes.

The only place I could find a completed picture was on the first page of this campus parking newsletter. That is the West Campus garage in the background.

Note the architectural treatments, gentle grades, and width of the passageway. Plenty of room for bikes and peds to pass. You can't see from the pic, but inside the high overhead has a very interesting wavy metal ceiling with lots of lights. The feeling is a very wide pedestrian boulevard that just happens to have a roof or canopy overhead. Alot of thought was put into quality of the pedestrian experience and user perception, to the degree that calling it a "tunnel" during the design phase was cause for a good verbal dressing-down.

There is also a smaller-scale tunnel here in the DFW area at a transit station. That one has stairs on one end and is not as wide open. But I like it because it does have an overhead opening to the sky in the center, which is in the median of the arterial. Good way to get light and fresh air into the passageway.

[nerudite]

Here's an idea, why not UNDERPASS the stinking road and put people back where they belong....ahead of cars Keep the people at grade and subject vehicles to sub-terrain conditions

We'll be doing this in one location actually, but with the slope of the land, we probably won't be able to underpass the road in both locations.

[ICT/316]

Interesting topic. An enclosed overpass with large windows, lots of light, elevator music, constant messages about safety, the use of CCTV in the tunnel and prosecution of criminals over the speakers, I think would be a great design. With it being enclosed, people are not exposed to the elements and debris can not be thrown onto the roadway. Debris being thrown onto the road ways is very serious. Underpasses just have that negative feel to them.

Bill


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