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時候，我每天花幾個小時在荷蘭最繁忙的高速公路上開車。 當我第一次在CBS網站上看到貨車數據時，它立即引起了我的注意：它可以回答我在經過漫長的一天工作后因交通擁堵而卡住的那些不太重要的問題。

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

在本文中，我們將特別探討貨車運輸的幾個方面，

• What are the types of common goods vehicles? How can we tell them apart using data?
  普通貨車有哪些類型？ 我們如何使用數據區分它們？
• What is the lifespan of a goods vehicle?
  貨車的使用壽命是多少？
• Why is there such a high volume of goods vehicles on the motorways nowadays?
  為什么當今高速公路上有如此大量的貨車？

一般信息 (General information)

As described on CBS website, the data provides information

如CBS網站所述，數據提供了信息

… 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.

…關于荷蘭貨車的總公里數(由荷蘭和外國車輛細分)以及荷蘭貨車的總公里數和平均年公里數(由荷蘭和外國領土細分)的數據。 卡車和公路拖拉機，車輛的壽命和負載能力進一步細分了所有數字。

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

在分析中，我們將主要使用以下方法回答問題：

• country of origin: Dutch or foreign vehicles
  原產國：荷蘭或外國車輛
• vehicle type: lorries or road tractors
  車輛類型：貨車或公路牽引車
• vehicle age: deducted from the year of construction
  車齡：從建造年份中扣除
• vehicle km territory: abroad or in the Netherlands
  車輛公里范圍：國外或荷蘭

貨車類型 (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.

原始數據集將貨車分為幾個組和子組。 為簡單起見，我們將它們視為卡車或公路牽引車。

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.

從上面的圖表可以看出，自2001年起，公路牽引車正在逐漸普及。2002年，公路牽引車的總公里數超過了卡車。2008年，公路牽引車的注冊量超過了貨車。2018年，公路牽引車的公里數已經超過是卡車的兩倍。

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？ 上圖比較了荷蘭境內和境外貨車和公路拖拉機的平均年公里。 從上圖可以看出：

• Road tractors are more involved in extra-territory transportation than lorries;
  公路拖拉機比卡車更多地參與了境外運輸。
• Road tractors tend to have larger annual kilometres than the lorries, both in and outside the Netherlands.
  在荷蘭國內外，公路拖拉機的年公里數往往比貨車大。

貨車的使用壽命 (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.

貨車的使用壽命是多少？ 除了直接回答這個問題外，我們將略微調整這個問題，并研究一下新構建的一半要注銷需要多長時間。

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.

上圖顯示了仍在使用的貨車在使用年限中所占的百分比。 在分析的車輛類型之間存在明顯的區別：50％的新型公路牽引車在使用9年后取消注冊； 對于卡車，發生在3年后，使用了12年。

為何今天有那么多貨車？ (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.

與荷蘭人談論高速公路擁擠時，我總是聽到“這是經濟蓬勃發展的標志”。 考慮到這一點，我研究了CBS數據以及世界銀行的GDP記錄。

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

上表顯示了2001年至2018年期間的GPD(當前美元)和貨車公里數。可以觀察到以下幾點：

• Vehicle km is highly correlated to economic growth: it increases during the economic boom and shrinks in the bust.
  車輛公里數與經濟增長高度相關：在經濟繁榮時期會增加，而在蕭條時期則會縮小。
• 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.
  公路運輸似乎引領了周期。 貨運從2014年開始復蘇，而經濟則在2015年后進入增長周期。同樣，交通里程在2017年前一年達到頂峰，而經濟在2018年達到頂峰。

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.

在新建或注冊車輛的數量上也可以觀察到類似的趨勢。 在2009年和2010年期間，附近建筑的數量大大減少了。 從2011年開始對新車的投資開始恢復，并在2015年恢復到危機前的水平。

我從數據中學到的 (What I learned from the data)

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

從探索性數據分析中可以學到一些內容，

• The data contains information about two types of goods vehicle: lorries and road tractors;
  數據包含有關兩種類型的貨車的信息：卡車和公路牽引車；
• Road tractor is gradually gaining popularity in recent years, with more road tractor entering the market than lorries;
  近年來，公路牽引車逐漸普及，進入市場的公路牽引車比卡車多。
• Road tractors are more involved in extra-territory transportation than lorries while lorries tend to travel more often within the country.
  公路牽引車比貨車更多地參與境外運輸，而貨車在該國境內旅行的頻率更高。
• Road tractors have larger annual kilometres than the lorries, both in and outside the Netherlands;
  在荷蘭國內外，公路拖拉機的年公里數均大于貨車。
• 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;
  在使用壽命方面，有9年后50％的公路拖拉機被注銷，而在服役12年后出現的卡車則被注銷；
• It is concluded that freight transport is highly dependent on the economy. The variation of the vehicle kilometers closely follows the economic cycle.
  結論是，貨運高度依賴經濟。 車輛公里數的變化緊隨經濟周期。

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

現在就這樣。 下一步：建立回歸模型以對車輛類型進行分類。

All the used scripts are available in the git repo.

git repo中提供了所有使用的腳本。