You know who else invested in infrastructure? Autobahn spending was key to Hitler's consolidation of power

In Highway to Hitler, Nico Voigtländer (UCLA) and Hans‐Joachim Voth (University of Zurich)'s 2014 paper analyzing the impact of the massive infrastructure investment in creating the Autobahn, the authors conclude that the major spending project was key to Hitler's consolidation of power.

They base their conclusion on the 1934 plebiscite, which greatly expanded Hitler's powers.

The effects are both large and likely to be causal. We find that the decline in
opposition was about 50% faster in districts with an Autobahn connection than in
the rest. By comparing changes in districts that would have been traversed by the
motorways planned in 1926 with those in areas that actually saw construction,
we also establish that roads added or altered by the Nazi planners are not
responsible for the additional vote shifts we document – the decline in
opposition was identical in Autobahn districts included in early plans and those
added after 1933. This rules out that the revised 1933 plans "chased" growing
support in some districts.

Why did motorway building reduce opposition to the regime? We cannot
directly establish the channels through which the Autobahn helped to win the
"hearts and minds" of Germans.  The Nazi regime prioritized road‐building as
an economic stimulus measure.  Original plans were for 600,000 workers to be
employed; the actual maximum was 125,000. Recent analysis suggests that
economic effects in the aggregate were modest (Ritschl 1998). The benefits in
terms of transport were also minimal – Germany had one of the lowest rates of
car ownership in Europe (Evans 2006).  

Nonetheless, it is possible that local effects were much larger. Workers were
initially housed in private homes in the villages and towns where the roads were
being built; barracks were only built later. Those employed in building the road
also spent money in inns and shops; construction crews organized film showings,
and construction sites became minor local attractions – a popular destination for
weekend trips (Eichner‐Ramm 2008).

Highway to Hitler [Nico Voigtländer and Hans‐Joachim Voth]

(via Marginal Revolution)