<story><title>Japanese railway company starts testing 249mph bullet train speeds</title><url>https://arstechnica.com/cars/2019/05/japanese-railway-company-starts-testing-249mph-bullet-train-speeds/</url></story><parent_chain></parent_chain><comment><author>cheerlessbog</author><text>Faster trains make longer distances competitive with air travel. Assuming a similar price per mile, the cutoff is T * deltaV where T is the extra time to travel to and from the airport and get through security and deltaV is the difference in speed. Assuming 3 hours and 250mph (500 - 250) the cutover is 750 miles.&lt;p&gt;Reality is less simple as price varies as well. In Europe the cutover (in time and price) seems about 200 miles [1] although the CO2 emissions are up to 30x higher by air. Of course speeds are lower, maybe 150mph which would suggest a 450mi cutoff.&lt;p&gt;[1] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;m.dw.com&amp;#x2F;en&amp;#x2F;trains-vs-planes-whats-the-real-cost-of-travel&amp;#x2F;a-45209552&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;m.dw.com&amp;#x2F;en&amp;#x2F;trains-vs-planes-whats-the-real-cost-of-...&lt;/a&gt;</text></comment>
<story><title>Japanese railway company starts testing 249mph bullet train speeds</title><url>https://arstechnica.com/cars/2019/05/japanese-railway-company-starts-testing-249mph-bullet-train-speeds/</url></story><parent_chain></parent_chain><comment><author>CPLX</author><text>Meanwhile, we still can’t take the subway to LaGuardia despite a few billion dollars in recent renovations.</text></comment>