Maryland Route 200 (MD 200), more commonly known as the Intercounty Connector or ICC, is a partially completed tolled freeway under construction in Maryland which connects Gaithersburg in Montgomery County and Laurel in Prince George's County. When completed, it will reach the community of Konterra just north of Beltsville. The highway was originally proposed in the 1960s as part of the Washington Outer Beltway. While other parts of the Outer Beltway were canceled, the ICC and the Fairfax County Parkway remained on master plans. The road's long history as an unbuilt proposed road stems from the controversy that has surrounded it over the years.

Proponents of the highway have claimed that it will improve the flow of interregional traffic, relieving traffic congestion on local roads. Opponents of the highway have claimed that the road will (with a few limited exceptions) harm significant traffic flow characteristics (such as increasing drive times, congestion, and costs in the form of tolls), will negatively harm the environment (with air, sea and land impacts), and will disrupt established communities through which it passes.

Fulfilling a 2002 campaign promise, Maryland Governor Robert Ehrlich pushed to begin construction of the road and conducted a formal groundbreaking in October 2006. With additional support from his successor, Governor Martin O'Malley, construction began on November 13, 2007. The first segment, from I-370 to Maryland Route 28, officially opened on February 23, 2011, while the extension to Interstate 95 opened on November 22, 2011.

MD 200 begins at a trumpet interchange with Interstate 370 (I-370) near Gaithersburg in Montgomery County, between its MD 355 and Shady Grove Road interchanges as a six-lane freeway. Several new ramps and collector-distributor roads were built between this interchange and MD 355. MD 200 continues northeast from there through Redland Station, turning east to pass over Shady Grove Road, and then under Redland Road, paralleling Mill Creek. This is the location of the eastbound toll gantry. MD 200 shortly curves to the east on the approach to the six-lane overpass for Olde Mill Run, which was built wide enough for a fourth lane in the eastbound direction. The Olde Mill Run overpass is the only section of MD 200 with full 12-foot (3.7 m) shoulders on each side. After the overpass, MD 200 turns southeast, passing under Needwood Road, before turning sharply back to the east as it passes under MD 115 (Muncaster Mill Road). The route, now running slightly to the southeast begins the approach to MD 97 (Georgia Avenue).

MD 200 turns more eastward, running towards North Branch Stream Valley Park, and passing over the north branch of Rock Creek and a second stream over a bridge. This is the location of the westbound toll gantry. The route enters the Norbeck area, and passes under Emory Lane. Just east of there is where a hybrid cloverleaf interchange with MD 97 (Georgia Avenue) is located. A park-and-ride may be built at this interchange. When the road opened in February 2011, it temporarily came to an end at a temporary traffic light located just east of MD 97 at MD 28 (Norbeck Road).

The route then curves southeastward, passing under MD 28 and Longmead Crossing Drive, running parallel to Wintergate Drive/Park Vista Drive. MD 200 then curves slightly more eastward toward Aspen Hill, where the freeway intersects MD 182 (Layhill Road), shortly after entering the Northwest Branch Recreational Park. The route travels though the park for a stretch, bridging the Northwest Branch three times (the second bridge also carries MD 200 over Bonifant Road), exits the park, and then turns eastward, passing under Notley Road. MD 200 then turns slightly to the northeast near Colesville and meets MD 650 at a single-point urban interchange.

MD 200 then continues eastward, passes through Upper Paint Branch Park and bridge several creeks, including the Paint Branch, and passes between several neighborhoods upon exiting the park. The route then passes under Old Columbia Pike with no access to this local road. Just beyond, MD 200 reaches a rather large interchange, made of many directional flyovers, with US 29. This interchange also adds connections to Fairland Road with both MD 200 and US 29. The route continues eastward, featuring a partial interchange with Briggs Chaney Road (westbound exit and eastbound entrance), and then, just after crossing the border into Prince George's County, it passes over the Little Paint Branch just south of the Fairland Recreational Park. The route then passes under Old Gunpowder Road.

The route then enters Calverton, where the expansive interchange with I-95 is located. The interchange, marked as Exit 31 on I-95, is mostly a cloverleaf hybrid, and features several collector-distributor roads built along I-95, stretching from Old Gunpowder Road south of the interchange to MD 198 north of it. The community of Konterra is planned for construction near this interchange.

Beyond I-95, MD 200 will narrow to four lanes. MD 200 curves sharply to the north and shortly curves sharply back to the east, and meets a diamond-interchange providing access to Virginia Manor Road. MD 200 then curves sharply to the southeast and will quickly end at a traffic-signal at US 1 (Baltimore Avenue) in Beltsville.

The entire length of MD 200 will be 18.8 miles (30.3 km) long, though the toll portion of the highway is only 13.8 miles (22.2 km) of this distance.

The Intercounty Connector uses all-electronic tolling, with tolls payable through E-ZPass or billed using Automatic Number Plate Recognition. ICC users without E-ZPass are mailed a bill to pay the toll along with a 50% surcharge for non-E-ZPass use (minimum of $1). The tolls along the full length of the road (between I-370 and I-95) vary by time of day, ranging from $1.60 overnight to $3.20 in off-peak daytime, and $4 at rush hour (for E-ZPass users; for others toll rates will be approximately 50% higher). Tolls were waived along the road between February 23 and March 7, 2011, and again between November 22 and December 4, 2011.

The ICC can be traced to plans developed in the 1950s for an Outer Beltway. The original Outer Beltway had been planned to pass south of the corporate limits of Rockville. Plans for most of the ICC alignment under construction in 2009 (between I-370 and the Trolley Museum site) were developed in the 1960s, and ran to the north and west of the original alignment. Even though the ICC does not cross the Potomac River, the new route was motivated in part by a desire to re-route an Outer Beltway crossing of the Potomac River upstream from the area of River Bend to Watkins Island.

In 1975, the the National Capital Region Transportation Planning Board (TPB) of the Metropolitan Washington Council of Governments endorsed a request from the State Highway Administration "for federal support of a $1.1 million planning and engineering study of the first 8-mile segment of the road" (then called the Outer Beltway), which was to "run from the Baltimore-Washington Parkway near Beltsville westward to a point near Interstate Rte 70S at Gaithersburg." However, the current route of the ICC follows that alignment only from a point near the site of the National Capital Trolley Museum east to US 1 (Baltimore Avenue) in Beltsville.

In 1980, the state of Maryland dropped the Outer Beltway from its plans, with the exception of the Intercounty Connector. In 1983, the federal National Capital Planning Commission (NCPC) formally requested that the eastern end of the ICC be shortened by four miles, so that the eastern terminus of the road would be at I-95, not the Baltimore-Washington Parkway. In 1984, Maryland Secretary of Transportation Lowell K. Bridwell designated land in Montgomery and Prince George's Counties as the future site of the Intercounty Connector so that the right-of-way would be preserved, even though Montgomery County Executive Charles W. Gilchrist had voiced very critical comments about the ICC as it was envisioned in 1983 – at least in part because he felt that construction of the ICC by the year 2000 was "infeasible", and advocated construction of a "shorter and less-costly" east-west highway instead.

Prior to Governor Parris N. Glendening declaring the ICC "dead" before leaving office in January 2003, two environmental impact studies had been conducted. In 1977, the Patuxent Wildlife Research Center expressed concerns about the impact that the ICC would have on its experiments. An initial environmental study was undertaken in the late 1970s, and extended into the 1980s. A second study was initiated around 1992, and a Draft Environmental Impact Statement (DEIS) was issued in 1997. The Final Environmental Impact Statement was drafted by 1989 but did not receive federal approval, leading to the abandonment of the study until a new study began in 1992; the 1992-1997 study pointed to a similar conclusion, though it was never completed. By 1997, millions of dollars had been spent on planning and preliminary engineering, but the only segments of the road that had been built were I-370 between I-270 and the Shady Grove Metrorail station on WMATA's Red Line.

After the 1997 ICC DEIS process was put on hold by Governor Glendening, much controversy resulted between groups and persons in favor of the ICC and those opposed. The ICC became a political issue in 1998, an election year in Maryland. A blue-ribbon committee entitled the Transportation Solutions Group (TSG) was formed in 1998 to tell the Governor's Smart Growth Sub-Cabinet about intermodal transportation that complied with state and regional goals. The TSG, chaired by Thomas B. Deen, former executive director of the Transportation Research Board, met at a series of meetings over about 14 months in 1998 and 1999. Policy suggestions and recommendations made by the TSG included that most of the group supports "providing high-speed bus transit, HOV and SOV access through a new east-west, value priced, limited-access parkway", with some opposition to the parkway and that the group had a divided opinion on a freeway, with most supporting it. The TSG had initially voted to oppose the ICC on its master planned route, but voted 10 in favor and 4 opposed in February 1999 to endorse a highway alternative with the condition that single-occupant vehicles be charged a toll. At its final meeting in June 1999, the TSG held a public hearing in College Park and voted 12 to 4 in favor of a "parkway-like highway from I-270 to I-95, following the general path of the ICC." The TSG also made a recommendation that a system of high-occupancy toll lanes (with variable pricing) be implemented on major freeways of the region, including the ICC, I-95, the Capital Beltway, I-270 and US 50.

On September 22, 1999, Glendening chose to reject the TSG recommendation, asserting that the project was "wrong" and "inconsistent with Smart Growth doctrine" and was quoted by The Washington Post as saying, "It is a proposal that has fractured our communities. It has pitted neighbor against neighbor. And it has created political gridlock while traffic gridlock has only worsened." Even though Glendening chose to ignore the TSG's primary recommendation, its work was not entirely in vain, as its efforts were to be cited prominently some years later in the ICC's Final Environmental Impact Statement (FEIS). The concept of a regionwide network of HOT lanes (to be called "variably priced highway lanes") was further developed by the the TPB, and a regional network (including the ICC) was described in a report published in February 2008. After rejecting the ICC, Glendening and opponents of the ICC then examined the possibility of selling its right-of-way, but proponents of the ICC would have been able to stop such a sale at the Board of Public Works, which must approve transactions involving the sale of state-owned real estate.

In 1999, staff to the Montgomery County Planning Board said that the ICC could be removed from master plans, but that such an effort would take "six or seven years" to accomplish. In November 1999, the Montgomery County Council discussed removing the ICC from master plans, and while five of the nine members were opposed to the ICC, the District 4 member, the late Marilyn Praisner, declined to agree to removal of the master-planned route, for fear that the so-called Northern Alignment (Corridor 2 in the 2005 Draft Environmental Impact Statement) would become a de facto ICC in the future. The effort by Montgomery County politicians to remove the ICC from its plans irritated powerful members of the Maryland General Assembly (notably Senate President Thomas V. "Mike" Miller), who discussed legislative measures that could be taken in the General Assembly to thwart such a move. In February 2000, an agreement between Montgomery County's politicians and members of the General Assembly reached an agreement "memorialized in two letters but not cast in stone" that the "... Council agreed not to take any action to kill the ICC during the next three years."

In 2000, Montgomery County Planning Board established the Transportation Policy Report and then the more-inclusive Transportation Policy Report II Task Force "... in an effort to establish a framework for future Master Plans and to help set priorities for future infrastructure." The TPR II Task Force had 33 members, including persons in favor of the ICC and those opposed. The TPR II Task Force listed the ICC in its recommended network, following a caveat that "If they are found feasible and ultimately judged desirable to implement, the priority of implementation could be established at that time. When the Montgomery County Council was briefed on the report, discussions quickly shifted to the ICC and the controversy associated with it. The ICC's FEIS makes specific reference to the work done by the TPR II Task Force.

The Maryland State Senate, in its 2002 session, passed Senate Joint Resolution 8, which asked Glendening to restart the ICC Environmental Impact Statement that had been put on hold in 1997. The Maryland House of Delegates passed an accompanying resolution, House Joint Resolution 10 with essentially similar provisions. The ICC study was not to be restarted until Glendening left office at the end of 2002.

In 2003, Governor Ehrlich followed through with his campaign promise to resurrect the ICC study and was allowed a fast track review process by the United States Secretary of Transportation, Norman Mineta. In addition to the election of Ehrlich, the Montgomery County Council that was seated at the end of 2002 had a 6-3 majority of members in favor of the project. Prior to the 2002 election, a majority had been skeptical (if not outright opposed) to the project.

On April 21, 2004, the TPB voted to include the ICC in future networks of the Washington region's transportation system for purposes of forecasting changes in air quality. On November 17, 2004, the TPB endorsed regional transportation plans which included the ICC, determining that the proposed plans met air quality goals and that funding for the project was adequate.

On July 11, 2005, Governor Ehrlich announced the state's preference to build the ICC along Corridor 1. Corridor 1 (approximately 80% of which is the Master Plan Alignment) has been on the books for decades; Corridor 2, also known as the Northern Alignment, was designed to reduce Corridor 1's impact on the environment. While the EPA gave Corridor 2 a higher environmental rating, it was eventually rejected by the state due to the increased number of homes and businesses that would have to be removed for its construction, because of negative environmental impacts on the Washington Suburban Sanitary Commission's Rocky Gorge Reservoir on the Patuxent River (which is a source of drinking water for much of the WSSC service area), and because it was not consistent with several approved and adopted Maryland-National Capital Park and Planning Commission master plans in Montgomery and Prince George's Counties.

On August 31, 2005, the Board of Public Works gave its approval to the Corridor 1 alternative, which allowed state funding of the project in accordance with Maryland's provisions (established by statute) for funding a "growth-related project" that is not entirely within Priority Funding Areas. In December 2005, controversy arose over the ICC's proposed toll rate. At a proposed 17 cents per mile, an end-to-end driver would have to pay about $6 a day for a round-trip (about $1,500 per year). On May 30, 2006, the Federal Highway Administration gave approval to the Corridor 1 plan, meaning that Maryland had satisfied "all environmental, economic and community requirements and that it can build the highway". The Baltimore Business Journal wrote, "Federal approval for the $2.4 billion connector came after Ehrlich made a direct request to President George W. Bush, who named the ICC as one of his priority projects. The president's direct attention prompted federal resource agencies to give the project a more timely environmental review."

The SHA constructed the ICC using separate design-build contracts for five phases.

The first of the five contracts was awarded on March 27, 2007. The contract, worth $478.7M, was awarded to Intercounty Constructors, a joint venture of Granite Construction Company, Corman Construction Inc. and G.A. & F.C. Wagman, Inc. Construction on the seven-mile (11 km) section between I-370 and MD 97 began in November 2007. Contracts for three other phases are active and the fifth phase involving collector-distributor lanes along I-95 has been deferred.

Requests for statements of qualification were issued for Phase A in December 2005, for Phase D in August 2006, and for Phase B in August 2007.

The selection of the second of the five contracts was announced on November 20, 2007. The contract, worth $513.9M, was awarded to IC3, a joint venture of Shirley Contracting Company, LLC; Clark Construction Group, LLC; Guy F. Atkinson Construction, LLC; Facchina Construction Company, Inc. and Trumbull Corporation. This work includes the ICC from a point west of US 29 to I-95, and interchanges with those routes.

On September 4, 2008, The Washington Post reported that the Contract B construction contract had been awarded on July 22, 2008 to a joint venture of Kiewit, Corman Construction, and G.A. & F.C. Wagman, at a total cost of about $559.7 million—reportedly 22% higher than previous estimates. The Post story went on to say that protest of this contract award was filed on July 30, 2008 by a joint venture that was not selected, though the bid price from the rejected group was lower. This protest may delay the start of construction on Contract B. On October 15, 2008, the Post reported that the protest was denied by state procurement officer Robert P. Gay and that the losing proposer will file an appeal with the Maryland State Board of Contract Appeals.

On September 12, 2008, the Post reported that Contract D ran into funding issues which will delay its construction. Contract D is associated with the proposed new interchange of I-95 and Contee Road (not part of the ICC). SHA Administrator Neil J. Pedersen stated that the "service roads can be delayed until the I-95 interchange has been built at Contee Road."

The first segment opened on February 23, 2011, ahead of its projected spring 2011 opening. No tolls were charged on the date of opening to March 6, 2011. On the opening morning, over 10,000 vehicles used the highway, and it went on to draw in 30,000 vehicles per day. During the first week of May, the tollway drew 11,490 vehicles per day, which is much less than the 21,000 projected. As a result, the state is launching a $1.4 million advertising campaign to promote the new highway. The second segment of the highway, from MD 97 to I-95 opened on November 22, 2011. The highway is expected to be extended to US 1 as late as 2014.

The $2.56 billion project is being financed from several sources, including the Maryland Transportation Authority (MdTA) revenue bonds, $1,232,500,000 (50.39%), GARVEE bonds $750,000,000 (30.66%), Maryland General Fund $264,910,000 (10.83%), Maryland Transportation Trust Fund $180,000,000 (7.36%), and Special Federal Funds $18,500,000 (0.76%)

MD 200 has gained opposition from several groups, including the Maryland General Assembly and the Prince George's County Council. Proponents of the highway have claimed that it will improve the flow of interregional traffic, relieving traffic congestion on local roads. Opponents of the highway have claimed that the road will (with a few limited exceptions) harm significant traffic flow characteristics (such as increasing drive times, congestion, and costs in the form of tolls), will harm the environment (with air, sea and land impacts), and will disrupt established communities through which it passes. Many of these assertions against the ICC were rebutted in detail in an appendix of the ICC's Final Environmental Impact Statement (FEIS).

Members of the Maryland General Assembly stated opposition in the Spring 2008 and Spring 2009 sessions, the 1998 session, and back to 1979, when a bill introduced in the General Assembly by Delegate Robin Ficker proposed to eliminate funding for a study of the ICC and the never-built Rockville Facility highway project. In 1980, a bill proposed by Delegate Idamae Garrott to forbid the Maryland Department of Transportation from even studying the matter of new highways running east and west between Montgomery and Prince George's Counties was tabled by the Montgomery County Delegation.

In the 1998 session, House Bill 817 was introduced to prohibit MDOT from spending funds or granting approvals to the ICC project, and House Bill 905 was intended to stop the operation of a toll highway altogether. Both bills failed to pass. In 2004, House Bill 732 proposed a similar statement to House Bill 817, extended to include the MdTA. The 2007 Special Session saw the offering of House Bill 37 to prevent construction of the road. Both of these bills also failed to pass. In the 2008 session, two bills proposing to cancel or delay the project were introduced – House Bill 1416 and House Bill 1471. House Bill 1471 proposed to eliminate funding for the road, and, if it had passed, would trigger "liquidated damage clauses that would require it to pay the contractors an estimated $80.0 million upon cancellation of the contracts," according to the Fiscal Note prepared by the state's Department of Legislative Services. Both bills failed.

In the 2009 session, a bill proposing to cancel funding for the ICC was pre-filed by Delegate Barbara A. Frush – House Bill 27. This bill had not attracted any co-sponsors nor had it been scheduled for a hearing. A similar bill, Senate Bill 753, was filed in the Maryland Senate by Sen. E. J. Pipkin and others. The Maryland Politics Watch blog opined that Pipkin's co-sponsorship of SB 753 may be related to his possible desire to run again for the U.S. House of Representatives Maryland District 1 seat. Both bills failed in the 2009 session. House Bill 27 received an unfavorable report from the House of Delegates Appropriations Committee on March 28, 2009; and no action was taken on Senate Bill 753 prior to adjournment on April 13, 2009, though a hearing was scheduled on March 18, 2009 before the Senate Budget and Taxation Committee.

The position of the County Council of Prince George's County in opposition to the ICC has been repeatedly cited by opposition groups, and its 2003 resolution on the subject, CR-32-2003, was adopted on June 10, 2003, where it called for alternatives to the road. In 2007, the Prince George's County Council passed resolution CR-59-2007, which repeats much of what was stated in CR-32-2003, including the language endorsing the ICC in Prince George's County.

In November 2006, environmental groups announced that they were preparing to file suit in order to delay or stop the project, and lawsuits aimed at halting construction were filed by environmental groups and affected residents, assisted in part by pro bono legal counsel from the Institute for Public Representation of the Georgetown University Law Center. One of those lawsuits was originally filed in the U.S. District Court for the District of Columbia (possibly as part of a forum shopping effort to avoid having the Fourth Circuit Court of Appeals hear the case on appeal - though the United States Court of Appeals for the District of Columbia Circuit, which would have heard any appeals from the D.C. federal court, had ruled against the Sierra Club and allied groups on similar legal issues in reversing a lower court on a case involving the proposal to reconstruct and widen the Woodrow Wilson Bridge in 1999) but Judge Gladys Kessler of the D.C. federal court ordered the matter transferred to federal court in Maryland on May 17, 2007 and the suits were consolidated. After hearings in October 2007, both lawsuits were dismissed in their entirety on November 8, 2007 by Judge Alexander Williams, Jr. of the U.S. District Court for the District of Maryland in a 105-page memorandum opinion.

The Baltimore Sun described the decision handed down by the court as a "victory for both Governor Martin O'Malley, who backs construction of the road, and a measure of vindication for former Governor Robert L. Ehrlich, who made it the top transportation priority of his administration." After the opinion was released, environmental groups opposed to the ICC stated that they would "consider their legal options before deciding whether to continue their battle" and some homeowners near the selected route expressed disagreement with the ruling of the court. On January 7, 2008, it was announced that Environmental Defense and the Sierra Club would appeal Judge Williams' decision to the United States Court of Appeals for the Fourth Circuit in Richmond, Virginia. In April 2008, persons and groups opposed to the ICC held an "Irish wake" to draw attention to the impact of the ICC, and an op-ed in The Diamondback was printed which raised objections to the ICC.

In June 2008, protests against the ICC were held at Dr. Charles R. Drew Elementary School in Silver Spring. The participants claimed that ICC construction should be halted because of air pollution impacts on pupils at the school, though it was reported that Governor O'Malley has no plans to do so. In August 2008, The Baltimore Sun published a letter to the editor from the executive director of the Coalition for Smarter Growth calling on the Maryland Department of Transportation to "cancel the ICC." In September 2008, The Sun's columnist Dan Rodricks wrote an anti-ICC opinion piece asserting that the ICC was the "Intercounty Anachronism". Rodricks' column was first rebutted by a letter to the editor by Montgomery County Councilmember Nancy Floreen (D-At Large) and then in a longer op-ed by SHA Administrator Neil Pedersen. Also in September 2008, The Gazette published an op-ed by state delegate Heather R. Mizeur (D-District 20) suggesting that the ICC be canceled. The Mizeur op-ed was rebutted in a response (also published by The Gazette) by Neil Pedersen in October 2008.

In November 2008, it was announced that Environmental Defense had dropped its appeal with the Fourth Circuit of the decision handed down by Judge Williams of the U.S. District Court for Maryland about a year earlier. In exchange for dropping the suit, the State Highway Administration agreed to fund new emissions-reduction technology used by public school buses in Montgomery County; and the SHA will also "sponsor a three-year study that involves installing air quality monitors along a major highway selected for its similar characteristics to the ICC and I-95." Press releases were issued by the State Highway Administration and Environmental Defense discussing the details of the legal settlement.

A major component of the ICC is environmental mitigation. In addition to work taking place near and in the right-of-way of the ICC, there are over 50 "off-site environmental and community improvement projects" that will be funded as part of the ICC engineering and construction budget.

In a letter to the editor of The Baltimore Sun, David Marks, a former official with the Maryland Department of Transportation, wrote that the SHA project team "...had the foresight to require substantial environmental improvements as part of the project, and they insisted on broad public input..."

One component of the mitigation is the replacement of parkland taken for the ICC with new land. Replacement lands intended to compensate for these losses include a large parcel of land in the Boyds area of Montgomery County owned by the Eugene B. Casey Foundation. However, the trustees of the Casey Foundation did not agree to the purchase of this parcel, so the State Highway Administration acquired the land by condemnation and the matter was reported as resolved in June 2008. In July 2008, controversy was reported on a similar subject. A 118-acre (0.48 km2) parcel of land near the intersection of MD 198 and Peach Orchard Road which had been condemned by the SHA in 1997 for possible use as the so-called Northern Alignment (Corridor 2) was conveyed to the Maryland-National Capital Park and Planning Commission to compensate for parkland which will be taken by the ICC. The former owner, Winchester Homes, filed a lawsuit contending that the SHA must offer to sell this land back to Winchester, and in May 2008, Judge S. Michael Pincus of the Montgomery County Circuit Court ruled that "the SHA was contractually obligated to offer Winchester Homes the chance to buy back the property." It was further reported that the state filed an appeal in June 2008.

In the February 2008 edition of the Successes in Stewardship newsletter, the Federal Highway Administration stated:

Since environmental impacts were the major barrier to prior ICC planning efforts, the third EIS team redefined the project-development approach to explicitly include environmental stewardship as part of the project's stated purpose and need. In order to fulfill the ICC's stated purpose "to help restore the natural, human, and cultural environments in the project area from the adverse effects of past development," lead-agency staff used context-sensitive design approaches to minimize or altogether avoid adverse impacts to wetlands and streams in the development of project alternatives.

At least one section of the ICC was re-routed from the master-planned route to reduce environmental impact, though the re-routing led to additional residences having to be condemned as a result.

Eastern box turtles (Terrapene carolina carolina) in the path of the ICC will be located with the aid of dogs trained to find them by scent and moved to other locations in Montgomery County near Boyds and Brookeville.

In a letter to the editor of The Gazette, SHA Administrator Neil Pedersen enumerated a list of environmental mitigation and community enhancements that SHA is funding as part of constructing the ICC.

The ICC is likely to force changes to the 14th hole of the Cross Creek Golf Club, which straddles the border between Montgomery County and Prince George's County. However, it was reported that the 14th hole was surveyed incorrectly, and part of it was mistakenly located on land set aside for the ICC.

In January 2009, it was reported that Eyes of Paint Branch (a group that has opposed the ICC) had recently demanded of the SHA that the contractors working to build the ICC comply with Montgomery County's regulations for the Upper Paint Branch Special Protection Area, which the State of Maryland has no legal obligation to follow.

Construction of the ICC has forced the National Capital Trolley Museum to relocate its car barns, shops, visitors center, and part of its track a short distance to the north. In 2006, the museum's development director made a public plea for relocation help and coordination in a Washington Post op-ed column. The museum suspended operations for relocation in December 2008 and resumed trolley rides in January 2010. In August 2009, the SHA held a public forum at the new and relocated trolley museum to describe the environmental mitigation aspects of the ongoing ICC construction project.

A major environmental concern along the entire ICC project is the impact of stormwater runoff on creeks and streams, during and after construction. Techniques and technologies to treat such water are known as best management practices (BMPs). State-of-the-art BMPs used along the ICC's construction project were described in an article in Land and Water magazine. Some of the methods being used to control runoff were described in a The Baltimore Sun "On the Outdoors" column, published after the writer toured several work areas along the ICC's right-of-way:

The ICC project employs teams of "stormbusters" to put down straw and grass seed and erect plastic silt fences in construction areas before it rains to prevent erosion. Solar-powered stream monitors give Baker and enforcement personnel a real-time reading of water conditions. Paved storm-water ditches in older neighborhoods abutting the highway will be replaced by grass-lined swales that will filter and cool the water before it enters tributaries.

The Sun column went on to describe financial incentives that will be paid to construction contractors that meet environmental goals and requirements.

As part of construction work, several archaeological sites have been found in the path of the ICC, including a Native American site near Georgia Avenue and Norbeck Road that contains artifacts dating to the Stone Age. and near US 29, the 19th century homestead of a freed slave, Melinda Jackson, containing numerous artifacts.

A bicycle trail has long been planned to run parallel to the highway, both in Montgomery County and Prince George's County.

However, in 2004, the SHA announced that it was dropping the ICC bike trail from its own plans due to cost and environmental footprint. Since then, there have been proposals to re-route some sections of the trail over existing surface streets, and to cut back or eliminate the trail for reasons of environmental impact and cost.

This move was harshly criticized by several groups, notably the bicycling community, who as The Washington Post states "have been promised much and given little" pertaining to the bicycle trail; however, it also believes that the county planners are assessing the situation seriously and will make the best decision. Eventually, on September 18, 2008, the Montgomery County Planning Board voted to endorse a trail following a route not adjacent to the ICC's route.

The Planning Board's proposal has been submitted to the Montgomery County Council for consideration as a master plan amendment. Bicycle advocates have stated their opposition to the proposal to remove parts of the bike trail immediately adjacent to the ICC. Later, in March 2009, the Montgomery County Council effectively endorsed both approaches, one being a route that did not follow the ICC (in particular, along the route crossing the Paint Branch) but also keeping in place plans for a path essentially parallel to the highway.

The first section of the bike path, from Needwood Road to MD 28 (Norbeck Road), primarily following the MD 200 right-of-way except for a section which follows Emory Lane to Georgia Avenue, opened on July 30, 2011.

Exit numbers and mile markers are a continuation of I-370 exit numbers.