Mile Markers

[dedekind32]

One of the features that I'd really like to see would be mile markers
and/or exit numbers in the geocoding service. You show the mile
markers and exit numbers in your maps, but there is no way that I know
of to search on these. Thanks.

[pamela (Google Employee)]

What would a query for those look like? (*I haven't driven in a while,
I don't recall how to refer to them).

It seems valid, you can file it as a feature request here:
http://code.google.com/p/gmaps-api-issues/issues/entry?template=Geocoding%20API%20-%20Feature%20Request

- pamela

[John Coryat]

Pamela,

In the US Interstate system, the highways have a marker every mile from the start of the highway to the end indicating which "mile" you've just passed. Recently, exit numbers have been realigned to match mile markers, so they are very useful. These markers are also used to locate stranded cars, accidents and congestion on the road. It would be great if there was a way of getting this info from the geocoder, the mile marker locations are not published anywhere that I've seen, even though they should be public record and would constitute discrete points on the road. Most GPS units will show this information, so it may be available.

The BTS road database has a pretty close approximation to these positions but nothing exact. They have the road segment length and the distance to the start of the road, so approximate locations can calculated although with very low precision, about 1/2 mile. Certainly not good enough to locate someone stranded, accident, work crew or officer giving tickets...

-John

[bratliff]

On Oct 2, 8:17 pm, John Coryat <cor...@gmail.com> wrote:
> Pamela,
>
> In the US Interstate system, the highways have a marker every mile from the
> start of the highway to the end indicating which "mile" you've just passed.
> Recently, exit numbers have been realigned to match mile markers, so they
> are very useful. These markers are also used to locate stranded cars,
> accidents and congestion on the road. It would be great if there was a way
> of getting this info from the geocoder, the mile marker locations are not
> published anywhere that I've seen, even though they should be public record
> and would constitute discrete points on the road. Most GPS units will show
> this information, so it may be available.
>
> The BTS road database has a pretty close approximation to these positions
> but nothing exact. They have the road segment length and the distance to the
> start of the road, so approximate locations can calculated although with
> very low precision, about 1/2 mile. Certainly not good enough to locate
> someone stranded, accident, work crew or officer giving tickets...
>
> -John

Hi John,

Last I checked, ME, NH, VT, MA, CT, RI, NY & PA were using
sequentially numbered exits. Perhaps the exits have been renumbered
since 2001.

The BTS *.dbf files contain two fields "BEGMP" & "ENDMP" which appear
to be "Mile Posts". Both are expressed in three decimal digits of
accuracy.

Berry

[John Coryat]

Berry,

I would bet that by now they have all been renumbered. They are in NY I believe, PA also. Most likely the rest as well.

The BTS numbers are great looking but they don't add up when the lengths of the road segments are analyzed. They are pretty good though, a lot better than nothing. What I'd love to see is 6 decimal accuracy figures for mile markers on either side of the road. Probably too much to ask.

-John

[bratliff]

On Oct 2, 10:17 pm, John Coryat <cor...@gmail.com> wrote:
> Berry,
>
> I would bet that by now they have all been renumbered. They are in NY I
> believe, PA also. Most likely the rest as well.
>
> The BTS numbers are great looking but they don't add up when the lengths of
> the road segments are analyzed. They are pretty good though, a lot better
> than nothing. What I'd love to see is 6 decimal accuracy figures for mile
> markers on either side of the road. Probably too much to ask.
>
> -John

Thanks John. You are right. I failed to check the actual numbers.

I am looking for definitions for:

Z
M
RECTYPE
VERSION
RECID
ORIGID
FNRECID
TNRECID
CTFIPS
SOURCE
LGURB
SMURB
SIGN1
SIGNT1
SIGNN1
SIGNQ1
SIGN2
SIGNT2
SIGNN2
SIGNQ2
SIGN3
SIGNT3
SIGNN3
SIGNQ3
LNAME
MILES
KM
FCLASS
RUCODE
STATUS
NHS
STRAHNET
FAC_ID
CONN_ID
CONN_DES
CONN_MILES
LRSKEY
LRSSEQ
BEGMP
ENDMP
AADT
THRULANES
OWNERSHIP
STFIPS
BTSVERSION

Several are obvious but "FCLASS" & "RUCODE" & "STATUS" have me
stumped. I do not know what the actual values mean. I could not find
any documentation. The TXT files were useless.

Berry

[John Coryat]

Berry,

It's all in the nhpnlin text file along with possible values.

-John