Casablanca is currently building tramways. A mode of transport that is suitable to medium sized cities. Many French and Italian cities of urban population around 200K-500K build tramways (think Toulouse, Bordeaux or Florence). Casablanca has a population of ~3.6 million people within its city limits of ~216sqkm. This is a larger population than most urban cores with metro systems. Put differently, that 3.6 million population lives in an extremely dense urban environment. Almost at the level of density of Paris and Manhattan. Yes, you read that right, Casablanca is an extremely dense city. It has a population density of around ~16K/sqkm but if you make the comparison to the city limits of Paris (population 2.1 million, ~87sqkm and ~25k/sqkm, minus bois de boulogne et bois de vincennes) the equivalent denser 2.1 million population neighborhoods in Casablanca have a population density of ~22K/sqkm (and around 98 sqkm) and comparing to Manhattan’s population of 1.7 million in ~56 sqkm (minus Central Park) for a population density of ~30K/sqkm, you can add up neighborhoods within Casablanca to a similar 1.7 million population in about ~72sqkm for a population density of ~24K/sqkm.

Paris and New York City have metro systems that carry 4-5 million passengers per day (pre-Covid). Casablanca on the other hand gets about ~200K passengers per day on its existing tramway lines. Granted New York City and Paris have much larger urban agglomeration populations (around ~20 million and ~11 million respectively). But Casablanca is at most half the size of Paris’ urban agglomeration at about ~5.5 million, but with a strong core urban density and a much lower rate of vehicle ownership (about 220 vehicles per 1000 inhabitants)¹. This also ignores Paris’ and NYC’s strong suburban rail ridership (the RER + Transilien in Paris adds more than another 1 billion in annual ridership).

Comparing to much smaller cities with tramways, Bordeaux with its 4 tramway lines has a daily ridership of ~280K per day and a population of just 260K and population density of ~5K/sqkm. Not a single one of Casablanca’s arrondissements have a density less than ~10K/sqkm. The entirety of the 3.6 million population lives in a neighborhood of at least double the population density of Bordeaux, a city 1/10 the population of Casablanca and at least 1/3 the population density, and yet it has more rail ridership than Casablanca.

This capacity difference becomes especially stark when comparing to cities smaller than Casablanca that actually have metro systems and not just tramways. For example, Montreal has a city population of 1.8 million and a population density of ~5k/sqkm, half the city population of Casablanca and almost a quarter of the population city density. Yet its metro system alone carried about 1 million passengers per day, more than 5x the volume of passengers of Casablanca.

Together, this speaks to an extremely high amount of latent demand for Casablanca. Tramways cannot sufficiently capture this latent demand. Both because of capacity constraints, but also because of speed of travel. Tramways in extremely ideal situations can at best can get to about 15K pphpd under peak loads. A back-of-the-envelope guess is that Casablanca’s two lines are doing about 10K pphpd on average. Suggesting that it’s already close to its peak capacity, which is no surprise given its population and density. Yet Casablanca is pursuing further expansion of its tramway system, adding two more lines. Given how resource constrained Morocco is, this strikes me as short-sighted. There is a greater need for higher capacity modes of transport, that can be built at cost premiums that are not exorbitant compared to tramways (see Marco Chitti’s discussions on when to build tramways). This is where expansion plans should be directed to.

The economic costs of undersupplying public transport in a dense city are large. Estimates of congestion, spatial misallocation via labor mismatch, loss of consumption, land value capture, can put the economic value of public transport at multiples of the cost of building such systems. Especially in the context of building out the core capacity of a network and not the marginal extension of a line in to low density neighborhood and the fact that Casablanca has population levels and density that is far beyond other cities with metro systems should make the case for high capacity public transport investment in Casablanca a no brainer. In Casablanca, tramways should be seen as a nice to have in a scenario where low density neighborhoods need better than bus levels of capacity. Not the main trunks of a public transit system. In this sense they are possibly a tenuous investment choice because of the crowding out of funds and opportunity cost of not building metro capacity.