# Transportation Deployment Casebook/2022/Puerto Rico
## Qualitative analysis
### Dominant transportation system in Puerto Rico
#### Streetcar

Streetcars are vehicles that run on pre-laid tracks on streets. Initially, streetcars were horse-drawn, but they evolved into steam-powered or electric-powered vehicles with the invention of steam engines and combustion engines. They were a popular form of public transit before automobiles and trains. Streetcars were known for their low rolling resistance due to steel wheels on steel rails and the simple guidance mechanism provided by flanges. People used them to travel around cities.

#### Transport before streetcar

Before the emergence of streetcars, walking was the primary mode of transportation within cities. Other options included horse-drawn carriages and wagons, which shared some similarities with streetcars in transporting people. However, they were less favored due to the lack of scheduling and dependency on pavement conditions.

#### Emergence of streetcar

The concept of streetcars originated in the early 1800s, but the first commercial streetcar was introduced by an American, John Stephenson, in 1832. Streetcar technology was similar to that of wagons but featured a fixed truck underneath, which required knowledge of ironworks at the time. The initial design of streetcars consisted of a single carriage with a capacity of 6-12 people, and it was driven by multiple horses. At the peak of the streetcar era, they became electric-powered and had larger capacities, which largely depended on the number of carriages.

#### Market development

The initial market for streetcars aimed to enable owners to transport their customers to their shops. Over time, streetcar owners recognized the potential of their service and began expanding routes to serve more areas. Builders and engineers focused on improving streetcar efficiency. For example, John Stephenson reduced carriage weight by half compared to the initial design and increased the number of horses from two to four.

#### Growth of streetcar

At the time, streetcars were the best option for people to travel within cities. The growth of streetcars was initially slow, as their value did not justify the cost. However, as engineers and builders improved the design and reduced the capital required, streetcars became a popular choice. Concurrently, investors were willing to risk their capital to build their own streetcar routes. The influx of private sector involvement led to traffic management and maintenance issues, as there was no centralized system. Consequently, local authorities often required streetcar owners to maintain road pavements regularly and allowed them to charge a flat fee for ticket sales as payment for maintenance. However, this policy resulted in a fixed ticket price for every streetcar system, causing problems for passengers who had to switch streetcars to reach their destination due to the lack of a centralized system. This issue was eventually resolved when local authorities took over the assets and maintained them using tax revenue. This move faced some opposition at the time, as it was seen as a step towards socialism.

## Quantitative analysis
### McGraw Electric Railway Manual - The Red Book of American Street Railway Investment
#### General information

A quantitative analysis was conducted on the growth of the streetcar system in Puerto Rico. The parameter focused on in this analysis was the track length of streetcars recorded in the McGraw Electric Railway Manual - The Red Book of American Street Railway Investment. The earliest record of streetcar tracks dates back to 1902. However, streetcars were already established in Puerto Rico in the 1880s during the Spanish colonization era. Puerto Rico was surrendered to the United States after the Spanish-American War in 1898. The streetcar system before the surrender was managed by Spanish investors who never submitted their information to the McGraw Electric Railway Manual. Therefore, the analysis only includes streetcar systems with records in the McGraw Electric Railway Manual.

#### World War 1

The railway system in Puerto Rico was heavily affected by World War 1 in 1914. Tracks were significantly damaged, requiring reconstruction and recovery to revive the entire streetcar system. However, some tracks were not economically viable to be reconstructed, resulting in a considerable drop in track length after 1914.

#### Results

A regression study was conducted on the track length. A three-parameter logistic function was used:
S(t) = Smax/[1+exp(-b(t-ti)]
where:
* S(t) is the status measure (e.g., passenger-km traveled)
* t is time (usually in years),
* ti is the inflection time (year in which 1/2 Smax is achieved),
* Smax is the saturation status level (choose the maximum length of the streetcar system recorded in the data),
* b is a coefficient to be estimated.
The results were split into two categories: including data after 1914 and excluding data after 1914.
| Intercept year | slope | R^2 |
| 1919 | 0.0417 | 0.15 |
| Intercept year | slope | R^2 |
| 1904 | 0.308 | 0.807 |

#### Discussion

The analysis including data after 1914 is invalid due to the low R^2 and an intercept year of 1919, which does not make sense. This result is reasonable because there was a drastic drop in data after 1914. The regression study assumes the number always increases as the year increases; thus, it is reasonable for the R^2 to be this low. However, the analysis excluding data after 1914 is valid. The R^2 is 0.8, which, although not high, shows a strong correlation of data. The t-statistic of the data is 6.77

## Reference

* 1 2 Wikipedia, Tram
* ↑ National Museum of American History, streetcar
* 1 2 Wikipedia, John Stephenson
* 1 2 Chicago's Public Transportation Policy, 1900-1940s
* ↑ Transportation Experience
* ↑ McGraw Electric Railway Manual
* ↑ Tram in San Juan