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问题很有趣,等高人

Pneumatic road tube counter

膜拜佩服 果然是老司机

这应该是让你减速用的吧?我也不晓得。貌似也见过很多次这样情况?反正每个人开过去都要刹车一下啊 不然底盘碰到 哈哈哈哈 我也不懂

那东西路上有见过,同样不知道是什么东西

{:5_142:} {:5_142:}

For counting vehicles using this road​:relaxed:

监测车流量的,楼上说了,Pneumatic road tube counter,压一次那个仪器就记录一次,大货车很多轴,尽管只有一辆,但是因为车体很长,所以也按多辆车算。

测车流量的, 提供traffic pattern 数据

那空中飞机拉的白雾线又是什么目的?

images.jpg

如果是平时飞机,那个线是 contrail,是水汽/云。 (不是航空表演拉的线 - 那个看似烟雾,其实是为了表演放的一种特殊的油)
以下摘自wikipedia
Contrails (/ˈkɒntreɪlz/; short for “condensation trails”) or vapor trails are line-shaped clouds sometimes produced by aircraft engine exhaust, typically at aircraft cruise altitudes several miles above the Earth’s surface. Contrails are composed primarily of water, in the form of ice crystals. The combination of water vapor in aircraft engine exhaust and the low ambient temperatures that often exists at these high altitudes allows the formation of the trails. Impurities in the jet exhaust from the fuel, including sulfur compounds (0.05% by weight in jet fuel) provide some of the particles that can serve as sites for water droplet growth in the exhaust and, if water droplets form, they might freeze to form ice particles that compose a contrail.[1] Their formation can also be triggered by changes in air pressure in wingtip vortices or in the air over the entire wing surface.[2]

Depending on the temperature and humidity at the altitude the contrails form, they may be visible for only a few seconds or minutes, or may persist for hours and spread to be several miles wide, eventually resembling natural cirrus or altocumulus clouds.[1] Persistent contrails are of particular interest to scientists because they increase the cloudiness of the atmosphere.[1] The resulting cloud forms may resemble cirrus, cirrocumulus, or cirrostratus, and are sometimes called cirrus aviaticus. Persistent spreading contrails are thought by some, without overwhelming scientific proof, to have a significant effect on global climate.[3][4]

飞行表演的那个一般是柴油

我一直以为是临时电线。。但是有些小地方 好像还有人站在路口数数的。 看样子又要规划懂工程了啊

这东西很烦也,开过去时还一颠一颠的,破坏车子的悬挂系统,真是不得好死:lol
在这个大数据的时代,这种low tech的东西还不赶紧淘汰,谷歌不用这些jb玩意一样对交通流量了如指掌,我就服了

楼上说了,就是调查公司放在路上测流量用的玩意儿

之前也以为是柴油。 记得很多很多年前看Leuchars airshow (那时每年show我们年年去报到的)时候广播里听的也是说柴油。
不过那天查的时候说是特殊的主要是植物来源的油,想想也对,因为这些油最终是要落下来的,而且飞行表演都是低空的,柴油是很‘脏’的油,下面观众肯定会吸入很多。 这些特殊的油降解比较快,对人体没有伤害。所以觉得应该是这些特制的油。

是反坦克地雷的引爆线,战争时通上电就不可以随便从上面开过去了。真的。

搜集行车数量, 速度的, 看看日后要不要加交通灯什么的, 给当局分析交通用的