I-380: old plans into SFO?

[DTComposer]

I noticed on the 1982 Caltrans highway map that I-380 had an eastward extension from US-101 - but not towards a proposed Southern Crossing like in the past. Instead, it crossed US-101, then turned south, running along today's McDonnell Road, then curving towards the terminals. In the 1986-1988-1990 maps there's something similar, but looks like it maybe included the full terminal access road from US-101.



It's a dashed line, indicating that they had a definite route selected. CHPW was out of publication by this time, and my initial internet searching couldn't find anything. It appears (per cahighways.org) that the legislative definition never changed during this period - the route has ended at US-101 since 1970.

Anyone have any information or thoughts on this?

[Max Rockatansky]

Shows as an adopted alignment also.  That's strange, I've never noticed this on the 1982 map before. 

[cahwyguy]

I noticed on the 1982 Caltrans highway map that I-380 had an eastward extension from US-101 - but not towards a proposed Southern Crossing like in the past. Instead, it crossed US-101, then turned south, running along today's McDonnell Road, then curving towards the terminals. In the 1986-1988-1990 maps there's something similar, but looks like it maybe included the full terminal access road from US-101.



It's a dashed line, indicating that they had a definite route selected. CHPW was out of publication by this time, and my initial internet searching couldn't find anything. It appears (per cahighways.org) that the legislative definition never changed during this period - the route has ended at US-101 since 1970.

Anyone have any information or thoughts on this?

Nice find. I'll put this on the pages as "Some maps show..." and steal your graphic (with credit, of course), while we search for more information.

[cahwyguy]

Researching this a bit. https://historysmc.pastperfectonline.com/archive/FC23B0EA-39F7-475C-A5CA-669920879914 might provide some information:

Scope & Content
04-San Mateo-186-X6.9-X7.6. Route 82 to Route 101, 1968-1974. Right of way acquisition documents for parcels of land in San Mateo County. This file shows undeveloped lands owned by the San Francisco International Airport in San Bruno needed for construction of the I-380 and Highway 101 Interchange.

Might be worth requesting. Thoughts? I don't know the process.

[cahwyguy]

I did a bunch of searching as well, including going through the "Going Places", published by Caltrans around 1983 (and discovered that Caltrans withdrew from AASHTO membership 1980-1983). I couldn't find anything as well. My guess is that the answer lies in two potential places: (1) The I-380 files at the Caltrans history library; (2) the EIRs for the construction of I-380 in that area, as those often summarize the history. There might also be information in the city archives (or airport archives) for the involved cities, as they would also have the adoption records and public notices. Hunting that down requires physical presence in Northern California, which I don't have.

One additional thought: We might drop a note to the MTC. I seem to recall that one MTC person might be on this forum; perhaps they will respond.

[bing101]

I noticed on the 1982 Caltrans highway map that I-380 had an eastward extension from US-101 - but not towards a proposed Southern Crossing like in the past. Instead, it crossed US-101, then turned south, running along today's McDonnell Road, then curving towards the terminals. In the 1986-1988-1990 maps there's something similar, but looks like it maybe included the full terminal access road from US-101.



It's a dashed line, indicating that they had a definite route selected. CHPW was out of publication by this time, and my initial internet searching couldn't find anything. It appears (per cahighways.org) that the legislative definition never changed during this period - the route has ended at US-101 since 1970.

Anyone have any information or thoughts on this?

The 1990 map shows I-380 right where the SFO terminal entrance are located. But SFO was not renovated until the mid 1990's. 

[Henry]

That's something new to me! I know about the westward extension from I-280, but never the (south)eastward one bending around the airport.

[DTComposer]

I did a bunch of searching as well, including going through the "Going Places", published by Caltrans around 1983 (and discovered that Caltrans withdrew from AASHTO membership 1980-1983). I couldn't find anything as well. My guess is that the answer lies in two potential places: (1) The I-380 files at the Caltrans history library; (2) the EIRs for the construction of I-380 in that area, as those often summarize the history. There might also be information in the city archives (or airport archives) for the involved cities, as they would also have the adoption records and public notices. Hunting that down requires physical presence in Northern California, which I don't have.

One additional thought: We might drop a note to the MTC. I seem to recall that one MTC person might be on this forum; perhaps they will respond.

I'm in that area semi-regularly, so perhaps I can detour to the archives if someone can figure out which one is most likely to have it. The land in question is in unincorporated San Mateo County, but owned by the City and County of San Francisco.

Scope & Content
04-San Mateo-186-X6.9-X7.6. Route 82 to Route 101, 1968-1974.

Currently, the postmile tool shows 380 ending at the end of the ramps to N. Access Drive at 6.76 (which aligns with the proposed westward extension to CA-1). So the 6.9-7.6 post miles could correspond to an extension to the terminals, OR the 6.9-7.6 could have been later re-numbered to the current postmiles.

[TheStranger]

As someone who lives in the area, I recently drove on the elevated slip ramp lanes from the terminals to 380 (which have been in place since the time the current international terminal was built) -

https://www.google.com/maps/@37.6177245,-122.3983379,3a,75y,347.15h,93.43t/data=!3m7!1e1!3m5!1s881ttqdyG8RDlYnE7qtlOg!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D-3.4253301338767983%26panoid%3D881ttqdyG8RDlYnE7qtlOg%26yaw%3D347.15298572829107!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI1MTEwMi4wIKXMDSoASAFQAw%3D%3D

There is also a companion southbound slip road from 380 to the terminal, but on lower ground:

https://www.google.com/maps/@37.6219032,-122.400719,3a,75y,172.05h,90.63t/data=!3m7!1e1!3m5!1sHgFS15cDJyhEVFBRDmZZoQ!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D-0.6340938268554339%26panoid%3DHgFS15cDJyhEVFBRDmZZoQ%26yaw%3D172.0481942003133!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI1MTEwMi4wIKXMDSoASAFQAw%3D%3D

Would these be considered essentially the proposed project in those maps, albeit not signed as a separate road from 101?

[cahwyguy]

This made me think to look at the postmiles. This is the link to the state highway lines database:

https://gis.data.ca.gov/datasets/77f2d7ba94e040a78bfbe36feb6279da_0/explore?location=37.635181%2C-122.401566%2C15.97

It doesn't look like the 380 postmiles extend as in the illustrated maps.

[bing101]

https://www.foundsf.org/index.php?title=San_Francisco_Airport


https://www.som.com/projects/san-francisco-international-airport-international-terminal/


Yes the current terminal for SFO opened in 2000. I-380 in the maps point to its route directed to where the terminal is located. The timeline matches up between the 1990's map of I-380's location when the terminal renovation was then a proposed project.

[lstone19]

As someone who lives in the area, I recently drove on the elevated slip ramp lanes from the terminals to 380 (which have been in place since the time the current international terminal was built) -

https://www.google.com/maps/@37.6177245,-122.3983379,3a,75y,347.15h,93.43t/data=!3m7!1e1!3m5!1s881ttqdyG8RDlYnE7qtlOg!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D-3.4253301338767983%26panoid%3D881ttqdyG8RDlYnE7qtlOg%26yaw%3D347.15298572829107!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI1MTEwMi4wIKXMDSoASAFQAw%3D%3D

There is also a companion southbound slip road from 380 to the terminal, but on lower ground:

https://www.google.com/maps/@37.6219032,-122.400719,3a,75y,172.05h,90.63t/data=!3m7!1e1!3m5!1sHgFS15cDJyhEVFBRDmZZoQ!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D-0.6340938268554339%26panoid%3DHgFS15cDJyhEVFBRDmZZoQ%26yaw%3D172.0481942003133!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI1MTEwMi4wIKXMDSoASAFQAw%3D%3D

Would these be considered essentially the proposed project in those maps, albeit not signed as a separate road from 101?

I lived in the Bay Area 1981-1997 and worked at the airport 1990-97 and I recall reading back then that those "slip ramps" were considered to be part of I-380 as opposed to being ramps of US 101.

Although additional ramps into the terminal were added as part of the International Terminal construction, many of those ramps go back to before my first visit to SFO in 1981. The basic flow in and out of the airport to/from 101 that existed in 1981 is still there. The "slip ramps" were there when I worked at the airport and my impression was they were built to eliminate the weaving section between the SFO entrance and I-380 as it existed then and that for whatever reason, were then considered an extension of I-380.