Editing Harvard Bridge (section)

===Superstructure replacement, 1980s===
After the failure of the [[Mianus River Bridge]] at [[Greenwich, Connecticut]] in 1983, the Harvard Bridge was shut down and inspected because it contained similar elements, specifically the suspended spans.<ref>{{cite news
  | last = Keane
  | first = Tom
  | title = It's the Engineering, Stupid
  | work = Boston Globe Magazine
  | publisher = [[Boston Globe]]
  | date = September 10, 2006
  | url = http://www.boston.com/news/globe/magazine/articles/2006/09/10/its_the_engineering_stupid/
  | access-date = September 11, 2006 }}</ref><ref>{{cite news
  | agency = [[United Press International]]
  | title = AROUND THE NATION; Boston's Harvard Bridge Closed to Heavy Trucks
  | work = The New York Times
  | date = July 6, 1983
  | url = https://www.nytimes.com/1983/07/06/us/around-the-nation-boston-s-harvard-bridge-closed-to-heavy-trucks.html
  | access-date = April 13, 2009 }}</ref>  Traffic was restricted to the inner two lanes due to the discovery of two failed hangers on span 14.  A few days later, all trucks and buses were banned from the bridge.<ref name=haer8 />

In 1986, a report was published containing the plan to replace the superstructure on the existing supports.  Alternatives considered were very similar to the [[#Engineering study, 1971-1972|1972 report]], and were similarly decided.<ref name=replacement7>Replacement, p.7</ref>  Structural modifications included an upgrade from four longitudinal girders to six of the same shape and replacement of a stairway with a handicapped pedestrian ramp on the Boston end of the bridge.<ref name=replacement>Replacement, p.4</ref>

Ramp "B", from southbound (Boston bound) bridge lanes to eastbound [[Storrow Drive]], caused traffic to merge onto Storrow Drive from the left (high speed) lanes using a short acceleration lane, causing safety issues.  The MDC requested elimination of this ramp.  Compared to overall bridge traffic of 30,000 vehicles per day, traffic on ramp B was found to be low, approximately 1,500 vehicles per day with a peak of 120 vehicles per hour.<ref name=replacement910>Replacement, page 4-6</ref>

The historic value of the bridge was considered significant, so the plan was to make the replacement superstructure appear similar, with similar railing and lighting.  In order to document the pre-existing structure, a Historic American Engineering Record (HAER) would be prepared.<ref name=replacment11>Replacement, p.11.  Note the use of the HAER document throughout this article.</ref>

Pier 12 was exhibiting inappropriate movement and was scheduled for reinforcement.<ref name=replacement5>Replacement, page 5</ref>

The work would be done in two phases.  Phase 1 would reinforce the downstream side of the bridge to allow MBTA bus traffic, and was expected to take 5 months.  Most of this effort would be spent on the underside of the bridge and would not affect existing traffic.  Phase 2 would replace the entire superstructure and was expected to take three construction seasons to implement.  Cost was estimated to be {{USD|20M}}<ref name=replacement5 /> (US${{formatnum:{{Inflation|US|20000000|1986|r=-6}}}} with inflation<ref name=inflation-US />).  Phase 1 finished in 1987, and Phase 2 in 1990.<ref name=globe1990>{{cite news
 | title = MASS. AVE. BRIDGE TO REOPEN FOUR LANES AFTER SEVEN YEARS
 | author = Ronald Rosenberg, Globe Staff
 | newspaper = Boston Globe
 | location = Boston, Massachusetts
 | date = September 12, 1990
 | page = 35 (METRO section)
 }}</ref>

<gallery caption="Before-and-after images" widths="225px" class="center">
File:Harvard Bridge, Spanning Charles River at Massachusetts Avenue, Boston ( Suffolk County, Massachusetts).jpg|Bridge viewed from the upstream Cambridge side in 1985.  Construction barrels restricting traffic from the outside lanes, and general wear and tear are visible (click on image to enlarge)
File:Harvard Bridge from Cambridge, 2009.jpg|Roughly the same view, in 2009.  Superstructure is in much better shape only 20 years after completion, than the 1985 superstructure was roughly 40 years after its most recent major work.
</gallery>
<gallery widths="225px" class="center">
File:Underside, centerline, 1985.jpg|Underside of the bridge in 1985.  Image shows how the bridge was originally built, and later modified, but before the superstructure was replaced.
File:Harvard Bridge, centerline, looking north, 2009.jpg|Underside of the bridge in 2009.  Image shows how the replacement superstructure was built, with six longitudinal girders, different bracing, etc.
</gallery>