I spent hours daily driving on one of the busiest motorways in the Netherlands when commuting was still a norm. When I first came across with the goods vehicle data on CBS website, it immediately attracted my attention: it could answer those not so important questions that I have always had, when stuck in a traffic jam after a long day of work, alongside the lorries.

在通勤仍然很普遍的时候，我每天花几个小时在荷兰最繁忙的高速公路上开车。 当我第一次在CBS网站上看到货车数据时，它立即引起了我的注意：它可以回答我在经过漫长的一天工作后因交通拥堵而卡住的那些不太重要的问题。

In this article, we will explore several aspects of goods vehicles transportation in particular,

在本文中，我们将特别探讨货车运输的几个方面，

• What are the types of common goods vehicles? How can we tell them apart using data?
  普通货车有哪些类型？ 我们如何使用数据区分它们？
• What is the lifespan of a goods vehicle?
  货车的使用寿命是多少？
• Why is there such a high volume of goods vehicles on the motorways nowadays?
  为什么当今高速公路上有如此大量的货车？

一般信息 (General information)

As described on CBS website, the data provides information

如CBS网站所述，数据提供了信息

… on total vehicle kilometres of goods vehicles in the Netherlands (broken down by Dutch and foreign vehicles) and data of total kilometres and average annual kilometres of Dutch goods vehicles (broken down by Dutch and foreign territory). All figures are further broken down by lorries and road tractors, by age of the vehicle and by load capacity.

…关于荷兰货车的总公里数(由荷兰和外国车辆细分)以及荷兰货车的总公里数和平均年公里数(由荷兰和外国领土细分)的数据。 卡车和公路拖拉机，车辆的寿命和负载能力进一步细分了所有数字。

In the analysis, we will answer the question using mainly the following:

在分析中，我们将主要使用以下方法回答问题：

• country of origin: Dutch or foreign vehicles
  原产国：荷兰或外国车辆
• vehicle type: lorries or road tractors
  车辆类型：货车或公路牵引车
• vehicle age: deducted from the year of construction
  车龄：从建造年份中扣除
• vehicle km territory: abroad or in the Netherlands
  车辆公里范围：国外或荷兰

货车类型 (Goods vehicle type)

The original dataset breaks the goods vehicle into several groups and subgroups. For simplicity concerns, we will treat them as either lorry or road tractor.

原始数据集将货车分为几个组和子组。 为简单起见，我们将它们视为卡车或公路牵引车。

From the charts above, it can be concluded that road tractor is gradually gaining popularity as of 2001. Road tractor total kilometres outnumber lorries in 2002. The registered amount of road tractor outnumbered lorries in 2008. In 2018, road tractor kilometres was already more than twice that of the lorry.

从上面的图表可以看出，自2001年起，公路牵引车正在逐渐普及。2002年，公路牵引车的总公里数超过了卡车。2008年，公路牵引车的注册量超过了货车。2018年，公路牵引车的公里数已经超过是卡车的两倍。

What about the annual average? The figure above compares the average annual kilometres in and outside the Netherlands, for lorries and road tractors. From the figure above, it is observed that:

那年平均呢？ 上图比较了荷兰境内和境外货车和公路拖拉机的平均年公里。 从上图可以看出：

• Road tractors are more involved in extra-territory transportation than lorries;
  公路拖拉机比卡车更多地参与了境外运输。
• Road tractors tend to have larger annual kilometres than the lorries, both in and outside the Netherlands.
  在荷兰国内外，公路拖拉机的年公里数往往比货车大。

货车的使用寿命 (The lifespan of goods vehicle)

What is the service life of goods vehicles? Instead of directly answering it, we will tweak this question slightly and investigate how long it takes for half of the newly constructed to become de-registered.

货车的使用寿命是多少？ 除了直接回答这个问题外，我们将略微调整这个问题，并研究一下新构建的一半要注销需要多长时间。

The figure above presents the percentage of the goods vehicle that remains in use, to the number of years in service. A clear distinction is present between the analyzed vehicle types: 50% of the newly constructed road tractors become de-registered after being in use for 9 years; for lorries, that occurs 3 years later when they are in use for 12 years.

上图显示了仍在使用的货车在使用年限中所占的百分比。 在分析的车辆类型之间存在明显的区别：50％的新型公路牵引车在使用9年后取消注册； 对于卡车，发生在3年后，使用了12年。

为何今天有那么多货车？ (Why so many goods vehicles nowadays?)

I always hear “it is a sign of booming economy” when talking to my Dutch fellows about the over crowded motorways. With this in mind, I looked into CBS data, in combination with GDP records from the World Bank.

与荷兰人谈论高速公路拥挤时，我总是听到“这是经济蓬勃发展的标志”。 考虑到这一点，我研究了CBS数据以及世界银行的GDP记录。

The chart above presents GPD (current USD)and goods vehicle km over the period from 2001 to 2018. A few observations can be made:

上表显示了2001年至2018年期间的GPD(当前美元)和货车公里数。可以观察到以下几点：

• Vehicle km is highly correlated to economic growth: it increases during the economic boom and shrinks in the bust.
  车辆公里数与经济增长高度相关：在经济繁荣时期会增加，而在萧条时期则会缩小。
• Road transport seems to lead the cycle. While freight transport recovery started in 2014, the economy entered the growth cycle one year later in 2015. Similarly, the traffic kilometers reached its peak one year earlier in 2017 while the economy peaked in 2018.
  公路运输似乎引领了周期。 货运从2014年开始复苏，而经济则在2015年后进入增长周期。同样，交通里程在2017年前一年达到顶峰，而经济在2018年达到顶峰。

A similar trend can also be observed in the number of newly constructed or registered vehicles. During the years of 2009 and 2010, there is a significant reduction in the number of near construction. Investment in new vehicles started to recover from 2011 and returned to the pre-crisis level in 2015.

在新建或注册车辆的数量上也可以观察到类似的趋势。 在2009年和2010年期间，附近建筑的数量大大减少了。 从2011年开始对新车的投资开始恢复，并在2015年恢复到危机前的水平。

我从数据中学到的 (What I learned from the data)

A few items can be learned from the exploratory data analysis,

从探索性数据分析中可以学到一些内容，

• The data contains information about two types of goods vehicle: lorries and road tractors;
  数据包含有关两种类型的货车的信息：卡车和公路牵引车；
• Road tractor is gradually gaining popularity in recent years, with more road tractor entering the market than lorries;
  近年来，公路牵引车逐渐普及，进入市场的公路牵引车比卡车多。
• Road tractors are more involved in extra-territory transportation than lorries while lorries tend to travel more often within the country.
  公路牵引车比货车更多地参与境外运输，而货车在该国境内旅行的频率更高。
• Road tractors have larger annual kilometres than the lorries, both in and outside the Netherlands;
  在荷兰国内外，公路拖拉机的年公里数均大于货车。
• With regards to the life span, 50% of road tractors becomes de-registered after 9 years while for lorries that occurs after being in service for 12 years;
  在使用寿命方面，有9年后50％的公路拖拉机被注销，而在服役12年后出现的卡车则被注销；
• It is concluded that freight transport is highly dependent on the economy. The variation of the vehicle kilometers closely follows the economic cycle.
  结论是，货运高度依赖经济。 车辆公里数的变化紧随经济周期。

That is it for now. Next step: build a regression model to classify vehicle types.

现在就这样。 下一步：建立回归模型以对车辆类型进行分类。

All the used scripts are available in the git repo.

git repo中提供了所有使用的脚本。