Results 1 to 11 of 11
  1. #1
    mtbr member
    Reputation:
    Join Date
    Feb 2015
    Posts
    7

    Emergency Location Markers (ELM) on Trails

    I'm working on the development of a trail in the Houston TX area. Since it will be remote from street addresses, I'd like to install markers so that, in the event of an incident, a call to 911 can bring emergency services directly to the site. In my travels, I have not seen an emergency location marker on any Houston area trails. Though an urban area, there are large stretches of trail that are miles from a road or street (often due to creek crossings).


    The research I've done so far indicates there are local systems (like the green Dallas Parks sign below) and the US National Grid system (blue signs below). I'm checking with local EMS and 911 systems to see if they recognize the national grid coordinates.


    I'd appreciate comments from those who have worked directly with the advocacy and development of ELM in other areas. Specifically, any feedback on the choice between a local system (e.g. Dallas) versus the US National Grid system versus other?? would be very helpful at this stage. Also, experience working through the issues in an area with a large number of overlapping jurisdictions (we have cities, counties, precincts, MUDs, drainage districts..) will apply directly to my effort.


    Thanks!
    Attached Images Attached Images   

  2. #2
    Bicycles aren't motorized
    Reputation: life behind bars's Avatar
    Join Date
    May 2014
    Posts
    3,866
    Longitude/latitude are universally recognized.
    Wanted, SRAM GX 2x11 rear derailleur

    It ain't supposed to be easy.

  3. #3
    mtbr member
    Reputation:
    Join Date
    Dec 2013
    Posts
    118
    Attached is a link to my local trail system's map. It has the location and GPS coordinates for ELM locations.

    We use a yellow/black sticker callouts on Carnsonite.

    https://files.dnr.state.mn.us/maps/s...s/sra00302.pdf

  4. #4
    mtbr member
    Reputation: HypNoTic's Avatar
    Join Date
    Jan 2007
    Posts
    341
    ELM is dependent on your Emergency Plan and how local services will handle the call. Most resort I work with have their own patrol/first aid so calls to 911 are redirected to them (during business hours) so they can handle the situation accordingly. ELM are typically a letter/number related to the closest junction of two trails or a mile marker / access point on longer trails. Most of our emergency plan are based on that.
    I build trails for moose & beaver
    PTBA member

  5. #5
    mtbr member
    Reputation:
    Join Date
    Aug 2009
    Posts
    54
    Why not get in touch with your local emergency personnel and ask them what would be best - i.e. what they would prefer? Best system in the world won't help if the 911 dispatcher isn't used to it.

    I'd also keep in mind that a seriously injured person - or a panicked riding buddy - may not be able to read long strings of numbers off accurately. Anything like QR codes is also a bad idea (requires working cell phone and coverage, and is trivially easy to hack).

  6. #6
    mtbr member
    Reputation:
    Join Date
    Jan 2004
    Posts
    600
    Any 911 call from a GPS equipped cell phone should automatically report its coordinates as part of the call. This information is communicated to first responders when they are dispatched.
    The only time this seems to fail is if the GPS is turned off or the phone was powered off just prior to making the call and the GPS didn't have time to calculate its position.

    I'd imagine, unless you're putting markers every hundred feet or so the likelyhood would be that a collision would happen out of sight of any markers. The money for the markers may be better spent elsewhere?

  7. #7
    I should be out riding
    Reputation: ACree's Avatar
    Join Date
    Sep 2004
    Posts
    1,785
    The recently opened Raging River trail system in WA state has coordinates on signs when crossing roads. AFAIK, first responders in the area are typically the fire department from the local city (the trail system lies on state forest land just outside city limits of a smallish town). You might be able to get more information on how/why they determined what type of coordinates to use on the signage from Evergreen Mountain Bike Alliance. evergreenmtb.org
    If it's not powered solely by you, it's motorized.

    Worshiping at the Church of Singletrack since 1993.

  8. #8
    mtbr member
    Reputation:
    Join Date
    Feb 2009
    Posts
    72

    Emergency Location Markers (ELM) on Trails.

    We have had a pretty good ELM system on our trails for quite a few years. With today's phone's all having GPS locations transmitted the need for ELM's is not as critical as in years past. I do think they still have a lot value as both way finder signing and rescue information.

    I would recommend you have a meeting with both the Land manager and the fire captain responsible for the area where the trails are located.

    The signing is something that will potentially need to be maintained after a 5 year period (depending on what signing materials you actually utilize.) Since all of our trails were on woodland areas our ELM signs were mounted on trees, this made it easier to post 30 miles of signs. However, over time and numerous ice and thunderstorms they do get damaged.

    We have signs posted at .25 mile intervals. The GPS lat/long's for each ELM are on file with the fire department emergency responders. Evacuations for many of the trails are most effectively done using the lake and a boat to ambulance combination.

    Here is what our 9"x 9" signs look like.

    One of our trails was recently had replacement signs put up that are smaller. On a bike they are not noticeable which I think defeats the benefit of doing it.
    Attached Thumbnails Attached Thumbnails Emergency Location Markers (ELM) on Trails-emergency-sign-2b.pdf  


  9. #9
    mtbr member
    Reputation:
    Join Date
    Jun 2013
    Posts
    33
    I'm curious what the OP finally used marker-wise.

    Access for emergencies in my local SoCal area is easy enough based on trail name info plus approx distance. We can easily plan based on that info since there are no real intermediate points of access. Cellular 911 data helps narrow things down but, due to coverage issues, the call often originates from a spot some distance from the accident site. Standard latitude/longitude can easily be converted to any coordinate system we need, but people often miss or transpose digits. We had a MTB over the side call a couple weeks ago where the initial coordinates provided by a bystander put the location in South Korea when it was first plotted... Rider went about 15' over the side. Bike went another 40'+ and we still haven't found where it landed.

  10. #10
    mtbr member
    Reputation:
    Join Date
    Jun 2010
    Posts
    38
    Quote Originally Posted by Surestick Malone View Post
    Any 911 call from a GPS equipped cell phone should automatically report its coordinates as part of the call. This information is communicated to first responders when they are dispatched. The only time this seems to fail is if the GPS is turned off or the phone was powered off just prior to making the call and the GPS didn't have time to calculate its position.
    A friend who is a first responder and a leading authority on USNG ELMs called my attention to this thread. No, as a general rule cell phones do not automatically send coordinates to 911.

    Most cell phones produced since 2011 get data from both USA satellites (GPS) and Russian satellites (GLONASS). The FCC prohibits use of Russian data for the purpose of 911.

    The wireless carrier handling a 911 call always delivers “phase 1” coordinates to the 911 call center. This is the location of the cell tower carrying the call. You with your bent bike and busted leg are some miles away from that tower.

    The carrier *might* determine “phase 2” coordinates and put them into a database where the 911 call taker can access them. Phase 2 coordinates are determined as follows. Your phone sends the raw data from only the USA satellites to a black box on the cell tower. That black box processes the USA-only raw data and determines - if possible - the phase 2 coordinates.

    In short, the FCC requires that phase 2 coordinates be ‘dumbed down’ compared to the coordinates produced by your phone which uses both USA and Russian satellites. More satellites = more data = better accuracy.

    Wait - it gets worse. The FCC allows carriers broad discretion to exempt themselves from the requires to provide phase 2 coordinates. And if you are in heavy forest or a canyon there might not be enough USA satellites visible to your phone to determine any phase 2 coordinates. Meanwhile your phone can determine coordinates with good accuracy without any trouble since it can see enough USA + Russian satellites.

    What does this all mean?

    Everyone needs some way to know (1) their latitude longitude in decimal degrees and (2) the accuracy value for those coordinates. Use whatever works best for you. But use something instead of nothing.

    If you cannot give 911 a good street address then you need to be able to give them coordinates in decimal degrees and the accuracy value.

    For some tips on calling 911 with a cell phone (do you know the 17 second rule?) you can open up my map software and click Menu ==> Tips for calling 911.
    https://mappingsupport.com/p2/gissurfer.php

    And regarding ELMs, here is a story out of northern Minnesota where a skier was saved by a USNG ELM sign.

    https://www.3m.com/3M/en_US/particle...9-afddf7f98277

    US National Grid (USNG) is the same as Military Grid Reference System (MGRS). The only difference is that USNG is written with spaces so it is easier to read. Since many first responders previously served in the army or marines, that already know USNG.

    The federal government is behind USNG since FEMA has adopted it for ground operations.
    https://mappingsupport.com/p/sar/FEM...10_15_2015.pdf

    Anyone trained in MGRS/USNG can go anywhere and immediately use that system. By contrast, the ‘bingo grid’ (see green sign posted by OP) for a park at town A is different than the bingo grid produced for a park at town B, etc.

    For more on USNG please see https://usngcenter.org/stateusng-maps/. I just traded email with those folks. They are in the process of rolling out new info regarding USNG ELM signs and then will update their website. If any of their links do not work, this is the reason.

  11. #11
    mtbr member
    Reputation:
    Join Date
    Jun 2013
    Posts
    33
    Quote Originally Posted by Jelf View Post
    .<snip> ......Everyone needs some way to know (1) their latitude longitude in decimal degrees and (2) the accuracy value for those coordinates. Use whatever works best for you. But use something instead of nothing.

    If you cannot give 911 a good street address then you need to be able to give them coordinates in decimal degrees and the accuracy value.

    For some tips on calling 911 with a cell phone (do you know the 17 second rule?) you can open up my map software and click Menu ==> Tips for calling 911.
    https://mappingsupport.com/p2/gissurfer.php

    And regarding ELMs, here is a story out of northern Minnesota where a skier was saved by a USNG ELM sign.

    https://www.3m.com/3M/en_US/particle...9-afddf7f98277

    US National Grid (USNG) is the same as Military Grid Reference System (MGRS). The only difference is that USNG is written with spaces so it is easier to read. Since many first responders previously served in the army or marines, that already know USNG.

    The federal government is behind USNG since FEMA has adopted it for ground operations.
    https://mappingsupport.com/p/sar/FEM...10_15_2015.pdf

    Anyone trained in MGRS/USNG can go anywhere and immediately use that system. By contrast, the ‘bingo grid’ (see green sign posted by OP) for a park at town A is different than the bingo grid produced for a park at town B, etc.

    For more on USNG please see https://usngcenter.org/stateusng-maps/. I just traded email with those folks. They are in the process of rolling out new info regarding USNG ELM signs and then will update their website. If any of their links do not work, this is the reason.
    This write-up on E9-1-1 and phase 1 or 2 location functions.

    Bottom line - some recognized reference coordinate is helpful. Decimal degrees/DD (e.g., 34.123456, 111.123456) is great and very helpful for any emergency response. Simpler than trying to give degree/minute/second info over a poor cell connection.

    USNG (Universal Transverse Mercator/UTM which underpins USNG) is great for signs, but is much less likely to be something the average person can provide to a 911 call taker or have available beyond the sign. Regardless of format, most SAR/FD/EMS responders can convert to a preferred format to, for instance, guide a helicopter to your location. A universal coordinate system like USNG/UTM (or lat /long) is the gold standard. Do not use unofficial trail references since they may not be widely known or there may be two (or more) First Water Trails in a jurisdiction.

    Unlike FCC rules on cellular 911, personal locator beacons (PLBs) make use of US, Russian, Indian and other satellites to gather location info. PLBs also do not require access to the cellular network.
    Last edited by mtnrsq; 2 Days Ago at 03:57 PM. Reason: Clarification

Similar Threads

  1. Location, Location and Location.
    By Bumpyride in forum Fat bikes
    Replies: 11
    Last Post: 01-15-2016, 02:55 PM
  2. Location, location, location - advice
    By iceboxsteve in forum Southeast/Midsouth - GA, TN, AL, FL, MS, LA, AR
    Replies: 1
    Last Post: 06-27-2014, 07:20 PM
  3. Location...Location...Location
    By FrontRanger in forum Colorado - Front Range
    Replies: 29
    Last Post: 08-17-2006, 08:49 PM

Members who have read this thread: 100

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2018 VerticalScope Inc. All rights reserved.