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Show HN: OpenTimes – Free travel times between U.S. Census geographies

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Re: Show HN: OpenTimes – Free travel times between U.S. Census geographies

#31

Post by anitil »

simonw wrote: post #15

OK the way you're publishing the data with Parquet and making it accessible through DuckDB is spectacular . Your README shows R and Python examples: https://github.com/dfsnow/opentimes?tab=readme-ov-file#using... I got it working with the `duckdb` terminal tool like this: INSTALL httpfs; LOAD httpfs; ATTACH 'https://data.opentimes.org/databases/0.0.1.duckdb' AS opentimes; SELECT origin_id, destination_id, duration_se…

Lately duckdb is becoming a serious competitor for my use of datasette because it's eliminating a step for most of my workflows - converting csv to sqlite.

I've been thinking about how to swap it in as a backend for datasette (maybe as a plugin?) but it seems inherently riskier as it needs to at very least be able to read a folder to list all the csvs available for my usecase. If I could hook that up with its native s3 support I'd be unstoppable (at work)

Re: Show HN: OpenTimes – Free travel times between U.S. Census geographies

#32

Post by dfsnow »

svcphr wrote: post #29

How did you decide on routing engine? I’ve used Graphhopper in the past — is OSRM an improvement?

I actually tried a couple different engines before landing on OSRM. I started with R5 (since it can also do public transit) then switched to Valhalla.

The main limiting factor was speed. Basically all routing engines except for OSRM are too slow to compute continent-scale travel time matrices. For reference, it took Valhalla around a week to finish 3 billion point-to-point pairs. OSRM did the same calculation in about 2 hours.

I can't speak to Graphhopper since I haven't tried it. Maybe something to test in the future!

Re: Show HN: OpenTimes – Free travel times between U.S. Census geographies

#33

Post by simonw »

anitil wrote: post #31
simonw wrote: post #15

OK the way you're publishing the data with Parquet and making it accessible through DuckDB is spectacular . Your README shows R and Python examples: https://github.com/dfsnow/opentimes?tab=readme-ov-file#using... I got it working with the `duckdb` terminal tool like this: INSTALL httpfs; LOAD httpfs; ATTACH 'https://data.opentimes.org/databases/0.0.1.duckdb' AS opentimes; SELECT origin_id, destination_id, duration_se…

Lately duckdb is becoming a serious competitor for my use of datasette because it's eliminating a step for most of my workflows - converting csv to sqlite. I've been thinking about how to swap it in as a backend for datasette (maybe as a plugin?) but it seems inherently riskier as it needs to at very least be able to read a folder to list all the csvs available for my usecase. If I could hook that up with its native…

I have a medium term ambition to make Datasette backends a plugin mechanism, and the two I am most excited about are DuckDB and PostgreSQL.

Re: Show HN: OpenTimes – Free travel times between U.S. Census geographies

#34

Post by timhigins »

dfsnow wrote: post #17
bobthepanda wrote: post #7

Any plans on adding public transit?

In the next year or so maybe. The biggest obstacles to adding public transit are: - Collecting all the necessary scheduling data (e.g. GTFS feeds) for every transit system in the county. Not insurmountable since there are services that do this currently. - Finding a routing engine that can compute nation-scale travel time matrices quickly. Currently, the two fastest open-source engines I've tried (OSRM and Valhalla)…

Can you just compute the travel times from each bus/train/tram stop and publish the individual or merged travel times? I guess the merging would be the hard part

Re: Show HN: OpenTimes – Free travel times between U.S. Census geographies

#35

Post by matthewfcarlson »

I’ve been meaning to make a much more searchable realty system (think Redfin with significantly more filters) and can look across the whole country not just in a specific zip code. This would be awesome as you could compute travel time between points roughly then filter out results more accurately
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