Mercury Vapor High Mast Lights

[jcn]

As I've discussed on here before, several interchanges on I-95 in Maryland used to have mercury vapor high masts, particularly on the interchanges between the beltways, which were there since that part of 95 opened up.  In addition, the JFK Highway portion also used to have mercury high masts at some interchanges that were similar to the ones between the beltways.  I wonder if those on the JFK were erected the same year the between the beltway part was built since I heard they were erected in the same decade, and like I said, they looked similar.  Also, if I recall correctly, I believe the Reading interchange on the PA turnpike used to have mercury high masts as well.  Those are not there anymore either.  This leads me to a question.  I'm curious to know where else did mercury vapor high masts used to exist? 

[Mdcastle]

Minnesota: I-90 at Worthington (the first installation in the state), Fish Lake interchange, and Crosstown / County 18 (todays US 169 and US 212). In the 1980s they started putting metal halide lamps of the same wattage in resulting in the interchange being lit as bright as day.

[jcn]

Minnesota: I-90 at Worthington (the first installation in the state), Fish Lake interchange, and Crosstown / County 18 (todays US 169 and US 212). In the 1980s they started putting metal halide lamps of the same wattage in resulting in the interchange being lit as bright as day.

You know, the ones at 169 and 212 aren't there anymore.

I wonder if the high masts on 95 in Maryland switched over to metal halide as well before they got taken down.  Same with the ones that used to be at the Reading interchange on the PA Turnpike.

[Mdcastle]

Worthington being installed about 1973. Valleyfair also uses old mercury vapor high-masts that have been lamped with metal halide. A parking lot I'd be more concerned about using non-protected arc tube lamps than along a highway.

[Henry]

Minnesota: I-90 at Worthington (the first installation in the state), Fish Lake interchange, and Crosstown / County 18 (todays US 169 and US 212). In the 1980s they started putting metal halide lamps of the same wattage in resulting in the interchange being lit as bright as day.

You know, the ones at 169 and 212 aren't there anymore.

I wonder if the high masts on 95 in Maryland switched over to metal halide as well before they got taken down.  Same with the ones that used to be at the Reading interchange on the PA Turnpike.

It is also possible that some of those were converted to high-pressure sodium (and again in the same wattages), which has been the dominant type of high-mast lighting since the 80s. Whatever the reason, mercury vapor high-masts are very few and far between these days.

Speaking of which, I remember reading about either I-35 or I-44 in OK having metal halide high-masts that may have been mercury vapor as well.

[jp the roadgeek]

MA tends to use them quite a bit, however many were used in the area of Mass Pike toll plazas, so they've been reduced.  The ones on I-91 between the CT border and the Forest Park curve have been replaced, but the ones near Exits 16-17 in Holyoke are still there.  Also see the ones near the I-495/US 3 interchange in the Lowell area are still there.  CT never used them that much; the only place I know of them are in the area of the I-84/CT 15 interchange in East Hartford, in Waterbury in the area of the CT 69 exit, and just south of the Gold Star Bridge on I-95 in New London.

[ET21]

Plenty in northeast Illinois, I-55 comes to mind for me. There's a smattering on other roadways, mainly IDOT controlled, but the Tollway recently put some up at IL-59 and I-88 at a DDI

[RobbieL2415]

MA tends to use them quite a bit, however many were used in the area of Mass Pike toll plazas, so they've been reduced.  The ones on I-91 between the CT border and the Forest Park curve have been replaced, but the ones near Exits 16-17 in Holyoke are still there.  Also see the ones near the I-495/US 3 interchange in the Lowell area are still there.  CT never used them that much; the only place I know of them are in the area of the I-84/CT 15 interchange in East Hartford, in Waterbury in the area of the CT 69 exit, and just south of the Gold Star Bridge on I-95 in New London.

I-391 in Springfield uses them just before it crosses the CT River.

[Rothman]

Technically, I-391 never touches Springfield.

[Beltway]

Has anyone seen an official statement from a DOT as to why they are replacing high mast lighting with standard luminaires?

[jeffandnicole]

Has anyone seen an official statement from a DOT as to why they are replacing high mast lighting with standard luminaires?

In their lighting design manual https://www.roads.maryland.gov/OOTS/tcddm_part-4.pdf , on page 2 (PDF page 4):

NEMA identification decals are placed on the outside of the ballast housing of each roadway luminaire. The color indicates the type of light source and the number indicates the lamp wattage...

Light Blue = Mercury Vapor, this lamp type is no longer used in new installations due to environmental reasons.

High mast lighting applications and guidance are also referred to on pages 11-12 (PDF 13-14) and pages 22-23 (PDF 24-25). It doesn't appear it's been completed banned, but appears to be highly discouraged.

[Beltway]

Has anyone seen an official statement from a DOT as to why they are replacing high mast lighting with standard luminaires?

In their lighting design manual https://www.roads.maryland.gov/OOTS/tcddm_part-4.pdf , on page 2 (PDF page 4):

NEMA identification decals are placed on the outside of the ballast housing of each roadway luminaire. The color indicates the type of light source and the number indicates the lamp wattage...
Light Blue = Mercury Vapor, this lamp type is no longer used in new installations due to environmental reasons.

High mast lighting applications and guidance are also referred to on pages 11-12 (PDF 13-14) and pages 22-23 (PDF 24-25). It doesn't appear it's been completed banned, but appears to be highly discouraged.

I have seen low pressure sodium lights used in high mast lighting.

Low level lighting appears to be the default installation.  I-95 between I-495 and I-695 was generally very rural when built so high mast lighting should have been fine back then.  When it came time to replace the lighting the development and other factors cited seem like MSHA would have chosen low level lighting.

Here are several quotes from that document. 

High mast lighting is typically installed at large complex interchanges within predominantly business or industrial areas.  It is associated with mounting heights that require special lowering gears to maintain the lights.  The lights typically require higher wattage lamps to produce the desired illumination levels on the pavement.  The light output usually provides an improved visual field negating the tunnel effect usually associated with low-level lighting, improved uniformity and reduced veiling glare.  The poles can be placed further away from the travel lanes, which decrease the possibility of off-the-road crashes.  Light trespass into surrounding neighborhoods however, is a usual source of complaints associated with high mast lighting.  High mast lighting will not be installed along state roadways unless required lighting levels cannot be achieved with low level lighting and justified by an engineering study, per the MSHA Lighting Guideline.

High mast lighting is only considered when photometrics cannot be met with 40' or 50' poles and employs an area type of lighting with groups of luminaires mounted on free standing poles or towers, at mounting heights varying from approximately 80 feet to 180 feet or more.   At these mounting heights, several high output luminaires develop a highly uniform light distribution. 

While there are many benefits of high mast lighting, there are also several cons.  High mast lighting can often lead to light trespass of non-roadway areas.  It may also require access roads to reach pole locations further off the road.  The lowering systems for high mast light poles also require maintenance.  Additionally, high mast lighting may have higher costs.  These factors should be considered when planning for high mast lighting on a project. The design and installation of high mast lighting equipment is more complex than conventional lighting.   Poles or towers, with lowering devices or other methods of luminaire servicing, require special design and maintenance considerations.

[02 Park Ave]

Metal halide lamps do provide the best color rendition.

[jcn]

Has anyone seen an official statement from a DOT as to why they are replacing high mast lighting with standard luminaires?

In their lighting design manual https://www.roads.maryland.gov/OOTS/tcddm_part-4.pdf , on page 2 (PDF page 4):

NEMA identification decals are placed on the outside of the ballast housing of each roadway luminaire. The color indicates the type of light source and the number indicates the lamp wattage...
Light Blue = Mercury Vapor, this lamp type is no longer used in new installations due to environmental reasons.

High mast lighting applications and guidance are also referred to on pages 11-12 (PDF 13-14) and pages 22-23 (PDF 24-25). It doesn't appear it's been completed banned, but appears to be highly discouraged.

I have seen low pressure sodium lights used in high mast lighting.

Low level lighting appears to be the default installation.  I-95 between I-495 and I-695 was generally very rural when built so high mast lighting should have been fine back then.  When it came time to replace the lighting the development and other factors cited seem like MSHA would have chosen low level lighting.

Here are several quotes from that document. 

High mast lighting is typically installed at large complex interchanges within predominantly business or industrial areas.  It is associated with mounting heights that require special lowering gears to maintain the lights.  The lights typically require higher wattage lamps to produce the desired illumination levels on the pavement.  The light output usually provides an improved visual field negating the tunnel effect usually associated with low-level lighting, improved uniformity and reduced veiling glare.  The poles can be placed further away from the travel lanes, which decrease the possibility of off-the-road crashes.  Light trespass into surrounding neighborhoods however, is a usual source of complaints associated with high mast lighting.  High mast lighting will not be installed along state roadways unless required lighting levels cannot be achieved with low level lighting and justified by an engineering study, per the MSHA Lighting Guideline.

High mast lighting is only considered when photometrics cannot be met with 40' or 50' poles and employs an area type of lighting with groups of luminaires mounted on free standing poles or towers, at mounting heights varying from approximately 80 feet to 180 feet or more.   At these mounting heights, several high output luminaires develop a highly uniform light distribution. 

While there are many benefits of high mast lighting, there are also several cons.  High mast lighting can often lead to light trespass of non-roadway areas.  It may also require access roads to reach pole locations further off the road.  The lowering systems for high mast light poles also require maintenance.  Additionally, high mast lighting may have higher costs.  These factors should be considered when planning for high mast lighting on a project. The design and installation of high mast lighting equipment is more complex than conventional lighting.   Poles or towers, with lowering devices or other methods of luminaire servicing, require special design and maintenance considerations.

So that probably explains why exit 93 is the only exit to why they put up new high masts as the toll plaza and the weigh stations are right by that exit.

Minnesota: I-90 at Worthington (the first installation in the state), Fish Lake interchange, and Crosstown / County 18 (todays US 169 and US 212). In the 1980s they started putting metal halide lamps of the same wattage in resulting in the interchange being lit as bright as day.

You know, the ones at 169 and 212 aren't there anymore.

I wonder if the high masts on 95 in Maryland switched over to metal halide as well before they got taken down.  Same with the ones that used to be at the Reading interchange on the PA Turnpike.

It is also possible that some of those were converted to high-pressure sodium (and again in the same wattages), which has been the dominant type of high-mast lighting since the 80s. Whatever the reason, mercury vapor high-masts are very few and far between these days.

Speaking of which, I remember reading about either I-35 or I-44 in OK having metal halide high-masts that may have been mercury vapor as well.

The old high masts on 95 in Maryland never switched over to HPS, they could have switched over to MH though.  The new high masts at exit 93 that I mentioned above are HPS.