Try with OpenStreetMap. It has one of the most complete coverage of the world. But I think tranform its data model to a ArcGIS Network will take time.

Country to Country is much different than City to City, and the capitals of countries are not necessarily the primary or most populous city in a country, nor are either of those symmetrically positioned withing the country ( like Moscow in Russia ). While there might nominally be some sort of sequence 'roads' that might form a shortest path in 2D, one of those roads may be a gravel track over a 15,000 ft pass closed for all but two months in the summer. Also, there might be roads, but that does not mean there is an actual route that can be traveled in a conventional sense because of border restrictions ( driving across the Chinese India border right now is problematic, for instance ). If there is a navigable route, travel time is not related to distance, it is dependent on road condition and traffic, customs at borders, etc. Many routes also have ferries for very short hops, and some go to rail, like through the Chunnel between London and Paris.

There are historical metrics for global travel times ( https://www.vox.com/2015/3/11/8187033/maps-travel-times ), and some go back to 1800s, and most medieval charts were also essentially travel ( sailing ) time maps. These are called isochrone or accessibility maps.

You could probably use a script in ArcGIS Online to iterate trough all the city pairs to save the routes if they exist or are supported.

What is your hypothesis, or theory you are trying to support, the research question?

Michael John Patrick Thank you, Michael. My research question is about how transports infrastructures affect country-pair shipping time, and in turn affect their economic activities.

I wish to use ArcGIS to estimate how the shipping-time change over time when more transport infrastructures were constructed.

Besides, I also wish to use ArcGIS to manually add some 'currently non-exist' transport infrastructures to see how would it affect the shipping time.

My interested time frame is around 2005-2020, which I guess digital maps of those years shall be somewhere available, I don't need shipping time decades or centuries ago.

Best if I can change the parameters in the estimation, e.g. km/hr of road, railway, ferry, stop time when passing boarder, etc.. I know these can be set in ArcGIS, even though I am not familiar with it.

I will also set some criteria (e.g. population of cities), when pairing up countries.

Some general things to consider.

The vast bulk of international trade ( and thus economic impacts ) is 'multi-modal'. That means just about everything ships via combinations of transport modes ( in order of cost per mile: pipeline, barge, ship, rail, truck, aircraft ) depending on 'efficiency' for the particular goods, and speed or even proximity may not be the driving force - Oil from the Bakken field might be collected by tanker trucks to a rail head, then onto a tanker to a storage terminal, loaded onto another tanker to a refinery, which uses a pipeline to another storage then onto trucks. this also can change on a daily or yearly basis depending on market conditions. Without even considering this, the accounting among countries is fairly complex ( see https://www.wto.org/english/res_e/statis_e/wts2017_e/wts2017_e.pdf and for the EU https://ec.europa.eu/eurostat/statistics-explained/index.php/International_trade_in_goods_by_mode_of_transport#Trade_by_mode_of_transport_in_value_and_quantity ) and note the EU is for 'value' not tons, etc. For the world, see the section 'Freight transport growth faces uncertainties' athttps://www.oecd-ilibrary.org/sites/57f51e1e-en/index.html?itemId=/content/component/57f51e1e-en - most of the world's international tonnage travels primarily by sea, and air barely appears in that chart compared to the 'by value' in the EU.

Any new or improved routes by mode that caused a historical global impact ( all those pairs of countries and the corresponding economic effects of all those country pairs ) are usually technological advances ( ultra-large container vessels ) or at the choke points ( improvements in the capacity of the Suez and Panama Canals ), and the dissolution of the USSR.

In a broad sense the infrastructure in the OECD has been very mature since the 1970's, but there might be some significant impacts in the developing world - new port facilities and paired rail lines in Africa, the interstate highway system in India and China. You should note how those statistical summaries break out the world into various regions and especially trade zones, especially for road freight - NAFTA ( Canada/USA/Mexico ), internal EU, etc. There probably isn't a lot of truck traffic going in and out of India, since it is in a state of conflict with most of it's neighbors and sheer geographic boundaries like mountain ranges and deserts. the only major shift I can think of of the top of my head is due to the global rise of temperature the Northern Sea Route and the Transpolar Passage could become viable alternatives for maritime freight routes. For trucks, possibly the Chinese 'Belt and Road' effort, but that seems to be stalling out as participating countries begin to object to the onerous financing terms.

So it is difficult because of the multi-modal aspect to separate the impact of road routes between any/ all pairs of countries, and then assign economic effects.

You might want to look at 'Global patterns of current and future road infrastructure' at https://iopscience.iop.org/article/10.1088/1748-9326/aabd42#erlaabd42s2 ... I don't know what you mean the reference to 'ArcGIS Pro' because it and many other GIS applications are basically the same, it is the data source that matters. The authors of the paper did make their's available, and it's seems fairly well documented: Global Roads Inventory Project (GRIP) at https://www.globio.info/download-grip-dataset

Filter on just highways and primary roads and you will get an idea for the possible long distance freight routes.

Try to go through google earth or do image classification for old image at the time you want

regards