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The Open NEC Project is a free and open-source Train Simulator 20xx mod that encompasses present-day Northeast Corridor (Washington, D.C. to Boston) content released for the game.

As the fastest and busiest rail corridor in the Americas, with trains screaming at speeds up to 150 mph, the Northeast Corridor relies heavily on cab signaling and onboard safety systems to keep an intricate mix of freight, Amtrak, and commuter trains below safe operating speeds. Computers constantly read the current speed, the positions of the controls, the status of the occupying signal block, and the locations of upcoming speed restrictions to determine the maximum safe speed for a given train. If the train's engineer violates that speed, or fails to respond to a change in driving conditions, then the system penalizes them—first with an alarm, and then, eventually, a full application of the service brakes.

Simply put, if your locomotive isn't beeping at you, sounding alarms, or even occasionally stopping itself on you, then you're not really driving a train on the Northeast Corridor. Unfortunately, when it comes to incorporating these essential and engaging systems into the gameplay of Train Simulator, Dovetail Games has a rather mediocre track record. While their 3D models include the correct displays, the logic that drives the systems themselves—the indicators they present, the sounds they make, the enforcement actions they take—has been consistently incomplete and inaccurate across every Northeast Corridor DLC released.

To be more specific, Dovetail has only partially modeled the corridor's Automatic Train Control (ATC) system, which is responsible for enforcing the maximum signal block speed. With respect to realism, Dovetail's ATC implementation is actually passable, but it often bugs out, leaving the train stuck with cab signals that freeze or brakes that won't release until the player turns ATC off and on again. And because every DLC release is developed and tested separately, every locomotive behaves ever so differently; indeed, the ATC for a given locomotive often doesn't function on other Northeast Corridor segments it wasn't tested on, even though in reality, the entire corridor uses the same set of cab signaling codes. Meanwhile, the Advanced Civil Speed Enforcement System (ACSES), which is responsible for enforcing the permanent track speed, is entirely absent, or only uselessly shows the same speed limit as the game's HUD does.

That's a harsh assessment, but fortunately, things don't have to be this way. By swapping the Lua code in each locomotive for open-source replacements, we can change the safety systems to behave as realistically as possible. Combined with Dovetail's assets, Train Simulator with Open NEC represents the ultimate Northeast Corridor driving experience, and it works with the routes you already own and the scenarios you have already downloaded.


Current status

Currently, the mod includes enhancements for each of these locomotives:

And provides full compatibility for each of these routes:


This website is divided into several sections. In the Get the mod chapter, you can find information on obtaining and installing the mod and when you can expect the next release. In the For players chapter, you can learn how to navigate the newly improved Northeast Corridor with your newly upgraded equipment. In the For contributors chapter, developers can find information on how to contribute to the project, as well as technical documentation on Dovetail's content.

At the project's GitHub page, you can file issues, view the roadmap, and browse the mod's source code.


Does this mod include any route or model improvements?

No. Currently, this project only includes improvements to the Lua scripting. Everything has been carefully constructed to avoid conflicting with other mods, especially Fan Railer's physics and sound mods.

Does this mod merge any routes together?


Help! I was driving in an external view and now my train is stuck in a penalty brake.

Open NEC enables all safety systems by default, which must be responded to, even when not driving inside the cab. On most locomotives, you can press Ctrl+D to disable ATC, and Ctrl+F to disable ACSES. Furthermore, Open NEC also adds an alerter subsystem that will sound an alarm if the controls are not manipulated within a certain period of time. There is no cab or keyboard control to disable the alerter, but you can press the exclamation mark on the HUD to "stick" the acknowledge button in the pressed position, which will prevent the alerter from activating.

Release history

The current stable release is Open NEC version 1.0.0.

v1.1.0 (April 22, 2022)

  • Fixed ZIP download failing to extract in Windows Explorer.
  • By popular demand, support for the Metro-North M7 EMU and Shoreliner cab car.
  • Metro-North locomotives:
    • ATC now correctly enforces 15 mph for Restricting and 80 mph for Clear/Normal.
  • Siemens ACS-64:
    • Fixed alerter not triggering the safety systems warning icon on the HUD.
    • Fixed desk and console light controls to behave prototypically.
    • Horn now correctly plays the bell and flashes the ditch lights.
    • Reinstated blended braking.
    • Enhanced compatibility with CTSL Railfan's enhancement pack:
      • The Suppression threshold is now set correctly for the automatic brake lever.
      • Pressing Shift+' moves the brake lever to the correct Suppression setting.
      • The safety systems alarm sound now plays continuously and correctly.
  • Acela Express:
    • Added fading effect for ditch lights.
    • Horn now correctly plays the bell.
  • NJ Transit locomotives:
    • Fixed ACSES braking curve overriding the ATC-enforced speed when approaching a speed limit drop.
  • All locomotives:
    • Added popup alerts that trigger when encountering a change in electrification.
    • Added popup alerts that trigger when starting and stopping a power change in a dual-mode locomotive.

v1.0.0 (January 27, 2022)

  • Support for the Metro-North M8.
    • Includes a notched master controller and, when used with Fan Railer's physics mod, blended braking.
  • ATC:
    • Fixed duplicate enforcement alarms.
  • ACSES:
    • Added acknowledgement for all civil speed drops.
    • Increased alert and penalty curve margins to 3 and 6 mph.
    • Cab displays now show a Stop aspect when nearing a Stop signal with a Restricting pulse code in force, to simulate a positive stop. There is a braking curve for the detection of positive stops, but there is no enforcement of the positive stop. Scripting limitations require OpenNEC to show a positive stop for all stop signals, not just ones at interlockings.
    • Reduced instances of "forgetting" the upcoming speed limit on heavier routes like New York-New Haven and Washington-Baltimore.
  • Acela Express:
    • Added a destination sign for New Carrollton, which Acela stopped at during its first few years of service.
  • EMD GP40PH-2B:
    • Changed strobe light pattern to be more prototypical.
  • GE Arrow III:
    • Restored ability to lower the pantograph using the cab control.
    • AI trains now turn on their bright headlights.
  • Amtrak locomotives:
    • Changed ditch lights to flash at a prototypical frequency.
  • NJ Transit locomotives:
    • Speed drop alarms can now be acknowledged and silenced.
    • Speed drop sounds now play at the beginning of the braking curve, not the end.
  • All locomotives:
    • For locomotives for which it would be unrealistic, sounding the horn no longer flashes the ditch lights.
    • Train brake status is now sent via consist message 10101, which enables the brake lights on Dovetail's Superliners and Ragno's Viewliner to work.

v0.7.0 (September 16, 2021)

  • Support for the NJ Transit Arrow III and GP40PH-2B.
  • Bombardier HHP-8:
    • Critical: Fixed nil error in script.
  • Bombardier ALP-45DP:
    • Reinstated exhaust fans.
    • Exhaust particles now increase or decrease depending on power output.
  • Siemens ACS-64:
    • Fixed wheelslip indicator being perpetually illuminated.

v0.6.0 (September 1, 2021)

  • Support for the NJ Transit ALP-45DP and ALP-46.
  • ATC:
    • Removed target deceleration rate requirement to achieve Suppression.
    • Fixed occasional failure to detect Suppression in locomotives with notched controllers.
    • Added support for Brandon Phelan's new Washington-Baltimore signal scripts.
  • Bombardier Comet V and Multilevel:
    • Changed speed bars to show the ACSES braking curve at all times.
    • Reinstated power mode changing when MU'ing with an ALP-45DP (see notes).
    • Reinstated blended braking and safety systems cut in/out.
    • Fixed HEP status and destination sign not being synced to other coaches.
  • MPI MP36PH:
    • Reinstated safety systems cut in/out.
  • All locomotives:
    • Removed the acknowledge auto-reset feature. Clicking the exclamation mark icon in the HUD now sticks the acknowledge control in the pressed state, as with other equipment in TS1.

v0.5.0 (May 22, 2021)

  • Support for the NJ Transit Comet V and Multilevel Cab Car.
  • ATC:
    • Logic has been changed to require target deceleration rate AND brake lever in suppression.
  • Amtrak ACS-64:
    • Fix overpowered train brakes.
  • Amtrak P32/P42 and MNRR P32:
    • Ditch lights will now flash when switched on.
    • Equipment speed limit raised to 110 mph for Amtrak locos.
  • Bombardier Multilevel:
    • Brake light indicators reinstated.
    • Manual door control reinstated.
    • Destination sign control reinstated.
    • MARC Multilevel destination signs texture swapped for MARC destinations.

v0.4.0 (April 23, 2021)

  • Support for the Amtrak and Metro-North P32AC-DM.
  • Support for the Amtrak P42DC (paths are set for the Washington-Baltimore version).
  • Official support for the Hudson Line route.
  • Amtrak Acela:
    • Critical: Fix broken destination signs and MU pantograph operation.

v0.3.0 (April 17, 2021)

  • Support for the Amtrak ACS-64.
  • Support for the MARC MP36PH and Multilevel Cab Car.
  • ACSES:
    • Temporarily disable positive stop as it is a nuisance in yards and stations.
  • Amtrak Acela:
    • Fix ditch lights rendering even when turned off.
  • Amtrak HHP-8:
    • Fix ditch lights rendering even when turned off.
    • Fix Xbox and Raildriver controls when running with Fan Railer's mod.

v0.2.0 (March 17, 2021)

  • Support for the Amtrak Acela Express.
  • Support for the Amtrak HHP-8.

v0.1.0-beta (March 9, 2021)

The first public release!

  • Support for the Amtrak AEM-7.
  • Support for all Dovetail Northeast Corridor routes.
  • Complete CSS, ATC, and ACSES implementations.

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